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+.help IRAF  Mar02  "V2.12EXPORT Release Notes"
+.sp 1
+.ce
+IRAF V2.12EXPORT Release Notes
+.ce
+January 25, 2002
+.ce
+Updated: March 25, 2002
+
+
+These release notes provide a summary of the major changes in V2.12.  This
+is a major release of IRAF and will be available for all supported platforms.
+More detailed technical documentation of all system changes will be found
+in the 'notes.v211' and 'notes.v212' files in the iraf$doc and iraf$local
+directories.  Detailed revisions notes for each application package are in
+the package directories in a file called Revisions, e.g. apphot$Revisions.
+
+.nf
+     1.  \fBHighlights of This Release\fR
+     2.  \fBIRAF System Revisions Summary\fR
+     3.  \fBCore IRAF Revisions Summary\fR
+    	  3.1 New Tasks
+    	  3.2 Existing tasks with new parameters/defaults
+    	  3.3 Existing tasks with new capabilities
+     4.  \fBNOAO Package Revisions Summary\fR
+    	  4.1 New NOAO Packages
+    	  4.2 New NOAO Package Tasks
+    	  4.3 Existing tasks with new parameters/defaults
+    	  4.4 Existing tasks with new capabilities
+     5.  \fBGeneral Package Changes\fR
+     6.  \fBGeneral Task Changes\fR
+     7.  \fBParameter File Changes\fR
+     8.  \fBDetails of Major System Changes\fR
+    	  8.1 FITS Kernel Changes
+    	  8.2 Large Image Support
+    	  8.3 Virtual Memory Cache
+    	  8.4 New Developer libraries
+     9.  \fBSystem Changes Which May Affect You\fR
+    	  9.1 Shared Library Version Incremented
+    	  9.2 External Package Recompilation
+    	  9.3 Parameter File Changes
+    	  9.4 Installation Script Changes
+    	  9.5 Help System Changes
+	  9.6 Image Display Changes
+	  9.7 PLIO Changes
+	  9.8 New Environment Variables Changes
+.fi
+
+
+.nh
+Highlights of This Release
+
+.nf
+    o \fBPixel Mask Support Added to FITS Kernel\fR
+        The FITS kernel was modified to add support for storing images in
+    	extensions as compressed pixel masks using the binary table extension.
+	These masks may be accessed like any other image and allow for tasks
+	to more easily store bad-pixel masks, regions masks, or error arrays
+	in the same image file as the science data.
+	
+    o \fBNew Pixel Mask Tasks\fR
+	Several new tasks have been added to the system PROTO package for
+	manipulating pixel masks:  
+
+	o MIMSTATISTICS allows image statistics to be computed while
+	    rejecting pixels specified by an input mask.  
+	o MSKEXPR task is a general-purpose mask expression evaluator
+	    similar to IMEXPR for images, but has builtin boolean region
+	    functions which can be used to set values inside or outside
+	    of certain geometric shapes.
+	o MSKREGIONS creates an output mask based on an input text de-
+	    scription.  Region descriptions can be composed of geometric
+	    shapes and logical operation on mask regions.
+
+	o OBJMASKS in the NPROTO package is a new task for detecting objects
+	    in an image and creating an output catalog or pixel mask of
+	    found objects.
+	
+    o \fBShared Memory Limitations Eased\fR
+	The IMAGES and DAOPHOT packages executables are now linked statically
+	to remove per-process memory limitations imposed by the IRAF shared
+	library on Sun and Dec Alpha systems.  Previously tasks such as
+	DAOFIND and IMCOMBINE were limited to 268Mb on Sun systems,  these
+	tasks can now use up to the machine memory limits.
+
+    o \fBImage I/O Buffer Sizes Increased\fR
+	Support for large image I/O was improved by changes to the internal
+	buffer sizes.  These buffers may automatically adjust to optimal
+	values for the image being accessed, however new environment variables
+	may be set to further tune the buffers at the user level.  Where
+	needed applications tasks were modified to take advantage of these
+	buffer size changes to force the imio buffer to be the size of the
+	input image.
+	
+    o \fBSimplified Installation Script\fR
+	The install script was rewritten to clarify the output and provide
+	some basic checking of the IRAF system setup prior to installation,
+	and to do some of the most common post-install configuration.  The
+	script will print an explanation of any errors it finds and suggest
+	corrective action, the hope is this will lead the user past some of
+	the most common installation errors.
+
+	In addition, the SYSINFO diagnostic script which does more extensive
+	checking of the system is also now part of the distribution.  This
+	script can be used to verify the system once the install is complete,
+	or to generate a report of the system configuration if needed by
+	site support.  An UNINSTALL script to remove iraf command links and
+	files created by the INSTALL script is also available to remove IRAF
+	from a machine.  All scripts are now installed in the hlib$ directory.
+	
+    o \fBNew HELP GUI and Output Options\fR
+	The HELP task was enhanced to have a new GUI option for XGterm
+	users.  This is essentially the XHELP task which has been available
+	in the GUIAPPS external package for some time, however the task is
+	fully backwards compatible and the text-mode output is still the
+	default.  As part of this work, help pages may also now be formatted
+	as either HTML or Postscript for web presentation or pretty-printing
+	to a hardcopy device.  The LROFF task was similarly modified to
+	provide direct conversion of lroff text sources.
+
+    o \fBDISPLAY Task Changes\fR
+	As part of the recent X11IRAF enhancements, the DISPLAY task and
+	others such as IMEXAMINE which interact with the display server were
+	modified to take advantage of the new features in XImtool V1.3.
+	These include support for 16 frame buffers (increased from 4 in
+	previous versions), and enhanced WCS readout capabilities.  The
+	changes are fully backwards compatible for use with older XImtool
+	versions or display servers such as SAOimage, SAOtng, or DS9 which
+	have not yet been updated.
+
+	X11IRAF V1.3 is being released simultaneously (but still separately)
+	with IRAF V2.12.  While V2.12 is fully compatible with older versions
+	of X11IRAF,  however users will need to upgrade both systems to take
+	full advantage of all the new features.  Users should consult the
+	X11IRAF Release Notes for details on what has changed there.
+	
+    o \fBNew Packages\fR
+	Several new packages are available in this release (see the NOAO
+	package change notes below for details):
+
+        - A new ASTCAT package for extracting astrometric and photometric
+	  calibration data from remote or local catalogs was added to NOAO.
+
+        - A new CRUTIL package for doing cosmic ray detection and removal
+	  package was installed in the IMRED package.
+
+        - A new QUADRED reduction package for QUAD format data was installed
+	  in the IMRED package.  This is a generalized replacement for the
+	  ARED.QUAD and XCCDRED external packages for processing CTIO and
+	  ESO FORS1 multi-amplifier data.
+
+        - A new OBSUTIL package was installed in NOAO.  This is a collection
+	  of tasks from various external packages which are useful to plan or
+	  carry out observations.
+
+    o \fBNew Developer Libraries.\fR
+	Several new libraries are available for SPP developers:
+
+      	- PSIO is a new Postscript text generation library installed in
+	  sys$psio.
+
+      	- CATQUERY is a remote astrometric/photometric catalog access lib
+	  installed in the XTOOLS utility library.  
+
+        - SKYWCS is a sky coordinate transformation library installed in
+	  the XTOOLS utility library.
+.fi	
+
+
+.nh
+IRAF System Revisions Summary
+
+.nf
+    o The IRAF shared library version number was incremented for SunOS
+	and Solaris systems.  See below for details on how this change
+	will affect external packages and locally-compiled software.
+
+    o The maximum number of nodes in a local iraf network was increased
+	from 320 to 512.
+
+    o The max number of open files in FIO, FIO_MAXFD, was increased from 
+      	256 to 4096.  This is the "hard limit" on the maximum number of
+      	open files in an IRAF process.
+
+    o The maximum number of host level open files, MAXOFILES, was increased
+      	from 64 to 256.  This is the maximum number of files that can be
+      	simultaneously open at the host level.  It determines the maximum
+      	number of files that can be simultaneously open by an IRAF process
+      	in the usual case.
+
+    o The number of keywords in a group header block for STF images (i.e.
+	the MAX_PCOUNT) was increased from 50 to 99 in the STF image kernel.
+
+    o Added support for the bitwise boolean operators: '&' (and), '|' (or),
+      	'^' (xor), and '~' (not/complement), to vectory expression evaluator
+      	fmtio$evvexpr.gy.  The IMEXPR task was modified to allow these new
+      	bitwise operations.
+
+    o Added new vector operators to VOPS library: alan, alank (logical AND)
+      	and alor, alork (logical OR).  These take any integer data as input
+      	(short, int, long) and return a logical (expressed as int) result.
+
+    o The 'imextn' environment variable will now accept upper-case extensions
+      	to specify image types.
+
+    o Host Command Execution: The way command line arguments are parsed 
+      	was modified to make it easier to set the value of a string parameter
+	to the null string. Whitespace is still skipped in @par files
+      	as before, however null strings are valid parameter values and will
+      	no longer cause a parameter prompt.
+
+    o The MKPKG special file list link support was enhanced to allow replacing
+	LFLAGS (the link flags variable) as well as the entire link line.
+	This makes is possible to write special-file list entries for packages 
+	which need e.g. to be compiled nonshared on certain platforms without
+	creating a platform specific mkpkg file for the package itself.
+
+    o The HSI zawset.c routine which controls a process working set size was
+	modified to automatically detect the physical size of system memory
+	(with a maximum return value of 2Gb).  The hard upper limit on memory
+	utilization defined by the unix kernel can be limited either by the
+	value return by the IRAF kernel (up to 90% of physical memory), or by
+	the value set in the user environment variable MAXWORKSET (given in
+	units of Mb).
+
+    o New stdimage display devices were added to support the display of Gemini
+	GMOS CCD data.  These devices are named 'imt45' thru 'imt49' and
+	correspond to the following frame buffer sizes:
+
+		imt45   2080 x 4644        # imt45|imtgmosccd
+		imt46   6400 x 4644        # imt46|imtgmos
+		imt47   3200 x 2322        # imt47|imtgmos2
+		imt48   1600 x 1161        # imt48|imtgmos4
+		imt49    800 x  581        # imt49|imtgmos8
+.fi
+
+.nh
+CORE IRAF REVISIONS SUMMARY
+
+.nh 2
+New Tasks
+.nf
+     imcoords.ccget - extract objects from a test file catalog
+     imcoords.ccstd - transform to and from standard astrometric coordinates
+proto.mimstatistics - do image statistics through a mask
+      proto.rskysub - sky subtract images using running mean or median
+      proto.mskexpr - general mask expression evaluator
+   proto.mskregions - create a mask from a list of region specifications
+.fi
+
+.nh 2
+Existing Tasks with New Parameters or New Parameter Defaults
+.nf
+ immatch.imcentroid - new parameter maxshift
+    immatch.imalign - new parameter maxshift
+     immatch.geomap - new parameter maxiter, default reject = 3.0 not INDEF
+     imcoords.ccmap - new parameter maxiter, default reject = 3.0 not INDEF
+  imcoords.imcctran - new parameter longpole
+       imutil.hedit - new parameter addonly
+imutil.imstatistics - new parameters nclip, lsigma, usigma, cache
+.fi
+
+.nh 2
+Existing Tasks with New Capabilities
+.nf
+ immatch.imcentroid - optionally rejects objects whose centers wander too much
+    immatch.imalign - optionally rejects objects whose centers wander too much
+     immatch.geomap - iterative rejection capability added
+     imcoords.ccmap - iterative rejection capability added 
+  imcoords.imcctran - support for non-zenithal projections added
+       imutil.hedit - support for add keyword only if new option
+imutil.imstatistics - support for iterative rejection and memory caching added
+      imutil.imexpr - support for bitwise operators or, and, xor, and not added
+.fi
+
+
+.nh
+NOAO PACKAGE REVISIONS SUMMARY
+
+.nh 2
+New NOAO Packages
+.nf
+      astcat - Astronomical catalog and surveys access package
+      crutil - Cosmic ray detection and removal package
+     obsutil - Observing utilities package
+.fi
+
+.nh 2
+New NOAO Package Tasks
+.nf
+      apphot.pcalc - Do arithmetic operations on a list of apphot databases
+   apphot.pconvert - Convert a text database to a tables database
+      apphot.pdump - Print selected fields from a list of apphot databases
+   apphot.pexamine - Interactively examine and edit an apphot database
+  apphot.prenumber - Renumber stars in an apphot database
+    apphot.pselect - Select records from an apphot database
+      apphot.psort - Sort an apphot database
+
+     astcat.aclist - List the supported astrometric catalogs
+    astcat.agetcat - Extract astrometry files from astrometric catalogs
+   astcat.afiltcat - Filter astrometry files derived from astrometric catalogs 
+   astcat.adumpcat - Catalog access debugging task
+     astcat.aslist - List the supported image surveys 
+     astcat.agetim - Extract FITS images from image surveys 
+     astcat.ahedit - Initialize the image wcs and set standard keywords
+    astcat.aimfind - Select images containing catalog objects
+    astcat.adumpim - Image survey access debugging task
+   astcat.aregpars - Default region parameter set
+   astcat.acatpars - Default astrometry file format parameter set 
+  astcat.afiltpars - Default astrometry file filtering parameters
+    astcat.aimpars - Default image data parameters
+   astcat.awcspars - Default image wcs parameters
+
+ crutil.cosmicrays - Remove cosmic rays using flux ratio algorithm
+  crutil.craverage - Detect CRs against average and avoid objects
+  crutil.crcombine - Combine multiple exposures to eliminate cosmic rays
+     crutil.credit - Interactively edit cosmic rays using an image display
+      crutil.crfix - Fix cosmic rays in images using cosmic ray masks
+     crutil.crgrow - Grow cosmic rays in cosmic ray masks
+   crutil.crmedian - Detect and replace cosmic rays with median filter
+   crutil.crnebula - Detect and replace cosmic rays in nebular data
+
+obsutil.psfmeasure - Measure PSF sizes from stellar images
+ obsutil.specfocus - Determine spectral focus and alignment variations
+ obsutil.starfocus - Determine direct focus variations from stellar images
+   obsutil.ccdtime - CCD photometry exposure time calculator
+  obsutil.pairmass - Plot airmass vs time for a given coordinate
+    obsutil.sptime - Spectroscopic exposure time calculator
+  obsutil.specpars - Spectrograph instrument parameters for sptime
+  obsutil.bitcount - Accumulate the bit statistics for a list of images
+  obsutil.findgain - Estimate the gain and readnoise of a CCD 
+   obsutil.shutcor - Shutter correction from images of varying exposure times
+
+   nproto.objmasks - detect and catalog objects in image
+.fi
+
+.nh 2
+Existing Packages and Tasks with New Parameters or New Parameter Defaults
+.nf
+            apphot - new package parameters wcsin, wcsout, and cache
+     apphot.center - new parameters wcsin, wcsout, cache
+    apphot.daofind - new parameters wcsout, cache
+     apphot.fitpsf - new parameters wcsin, wcsout, cache
+     apphot.fitsky - new parameters wcsin, wcsout, cache
+       apphot.phot - new parameters wcsin, wcsout, cache
+   apphot.polymark - new parameters wcsin, wcsout, cache
+   apphot.polyphot - new parameters wcsin, wcsout, cache
+      apphot.qphot - new parameters wcsin, wcsout, cache
+    apphot.radprof - new parameters wcsin, wcsout, cache
+      apphot.wphot - new parameters wcsin, wcsout, cache
+     apphot.txdump - replaced by pdump, available as a hidden task
+
+astutil.setairmass - new parameters ra, dec, equinox, st, ut, scale
+
+           daophot - new package parameters wcsin, wcsout, wcspsf, and cache
+   daophot.addstar - new parameters wcsin, wcsout, wcspsf, and cache
+   daophot.allstar - new parameters wcsin, wcsout, and wcspsf
+   daophot.daoedit - new parameters cache
+   daophot.daofind - new parameters wcsout, and cache
+     daophot.group - new parameters wcsin, wcsout, wcspsf, and cache
+     daophot.nstar - new parameters wcsin, wcsout, wcspsf, and cache
+      daophot.peak - new parameters wcsin, wcsout, wcspsf, and cache
+      daophot.phot - new parameters wcsin, wcsout, and cache
+       daophot.psf - new parameters wcsin, wcsout, and cache
+   daophot.substar - new parameters wcsin, wcsout, and cache
+.fi
+
+.nh 2
+Existing Tasks with New Capabilities
+.nf
+     apphot.center - coordinate system support, optional image cacheing
+    apphot.daofind - coordinate system support, optional image cacheing
+     apphot.fitpsf - coordinate system support, optional image cacheing
+     apphot.fitsky - coordinate system support, optional image cacheing
+       apphot.phot - coordinate system support, optional image cacheing
+   apphot.polymark - coordinate system support, optional image cacheing
+   apphot.polyphot - coordinate system support, optional image cacheing
+      apphot.qphot - coordinate system support, optional image cacheing
+    apphot.radprof - coordinate system support, optional image cacheing
+      apphot.wphot - coordinate system support, optional image cacheing
+
+astutil.setairmass - ra, dec, equinox, st, ut, scale are no longer hardwired
+ astutil.rvcorrect - more flexibility in setting ut
+
+   daophot.addstar - coordinate system support, optional image cacheing
+   daophot.allstar - coordinate system support
+   daophot.daoedit - optional image cacheing
+   daophot.daofind - coordinate system support, optional image cacheing
+     daophot.group - coordinate system support, optional image cacheing
+     daophot.nstar - coordinate system support, optional image cacheing
+      daophot.peak - coordinate system support, optional image cacheing
+      daophot.phot - coordinate system support, optional image cacheing
+       daophot.psf - coordinate system support, optional image cacheing
+   daophot.substar - coordinate system support, optional image cacheing
+.fi
+
+
+.nh
+General Package Changes
+
+.nf
+\fBNOAO\fR
+
+  \fBONEDSPEC\fR
+      More than 999 apertures are now allowed.
+
+  \fBAPPHOT\fR
+      Coordinate Support:
+	  All the apphot tasks have been modified to accept input coordinates
+	  in the logical, tv, physical, or world systems, and to write output
+	  coordinates in the logical, tv, or physical coordinate systems. One
+	  consequence of this is that the apphot tasks will now work correctly
+	  on image sections in interactive mode. Another is that users can now
+	  work directly on image sections while preserving the coordinate
+	  system of the parent image.
+
+      Image Cacheing Support:
+    	  All the apphot tasks which accept image pixel input have been mod-
+	  ified to optional cache the entire input image in memory. Cacheing
+	  may significantly improve the performance of tasks where many random
+	  access operations are performed.
+
+      File and image name directory information removed from output files
+    	  All the apphot tasks have been modified to strip directory infor-
+	  mation from the image and coordinate file names written to the output
+	  files, to the terminal, and to the plot headers. The colon commands
+	  will still read and write full image and coordinate file path names.
+
+      New PTOOLS Tasks Added
+        The ptools package tasks pcalc, pconvert, pdump, prenumber, pselect
+        and psort were added to the apphot package. The functionality of the
+        old txdump task as been replaced by the pdump.  TXDUMP is still avail-
+	able as a hidden task.
+
+   \fBASTCAT\fR
+      The astcat package is a set of tasks for extracting astrometric and
+      photometric calibration data from remote or local catalogs, filtering
+      the data, extracting FITS images from remote or local surveys, and adding
+      standard keywords to the extracted images.  There is also a task for
+      selecting images which contain catalog objects and locating the catalog
+      objects in the image.
+
+  \fBIMRED.CRUTIL\fR
+      Cosmic ray detection and removal package.  This package includes new
+      tasks and links to tasks from other package.  It replaces the CRUTIL
+      external package.
+
+  \fBIMRED.QUADRED\fR
+      Reduction package for QUAD format data.  This replaces the ARED.QUAD
+      and XCCDRED external packages for processing CTIO and ESO FORS1 multi-
+      amplifier data.
+
+  \fBDAOPHOT\fR
+    Coordinate Support
+    	All the daophot tasks have been modified to accept input coordinates
+    	in the logical, tv, physical, or world systems, and to write the output
+    	coordinates in the logical, tv, or physical coordinate systems. One
+    	consequence of this is that the daophot tasks will now work correctly
+    	on image sections in interactive mode. Another is that users can now
+    	work directly on image sections while preserving the coordinate
+    	system of the parent image.
+
+    Image Cacheing Support
+    	All the daophot tasks which accept image pixel input have been modified
+	to optionally cache the entire input image in memory. Cacheing signif-
+	icantly improves the performance of the tasks when many random access
+	operations are performed.  The cacheing already performed by the
+	ALLSTAR task is unchanged.
+
+    File and image name directory information removed from output files
+    	All the daophot tasks have been modified to strip directory information
+    	from the image and coordinate file names written to the output files,
+    	to the terminal, and to the plot headers. The colon commands will still
+    	read and write full image and coordinate file path names.
+
+  \fBOBSUTIL\fR
+	New observing utilities package.  This collects tasks from the NMISC,
+	SPECTIME, PROTO, and NLOCAL external package which are useful to
+	plan or carry out observations.  The new tasks are:
+
+               PSFMEASURE    STARFOCUS   SPECFOCUS    CCDTIME       
+               PAIRMASS      SPTIME      BITCOUNT     FINDGAIN    
+               SHUTCOR
+
+  \fBOBSOLETE\fR
+	o  Added tasks OIMCOMBINE and OIMSTATISTICS which are the previous
+	   versions from V2.113b system
+	o  Deleted the ODISPLAY task
+.fi
+
+
+.nh
+General Task Changes
+
+.nf
+\fBNOAO\fR
+  \fBONEDSPEC.SPLOT\fR
+      Rather than refusing to evaluate errors when there is negative data,
+      negative data is treated as zero.
+
+  \fBASTUTIL.SETAIRMASS\fR
+      Modified to have greater flexibility in selecting the keyword defining
+      the universal time.  New parameters define the keywords for RA, dec,
+      equinox, siderial time, universal time, and astrospheric scale height.
+
+  \fBASTUTIL.RVCORRECT\fR
+      Modified to have greater flexibility in selecting the keyword defining
+      the universal time.
+
+  \fBIMRED.ECHELLE.ECIDENTIFY\fR
+      Help page describes how to externally evaluate the dispersion fcns.
+
+  \fBIMRED.CCREDRED.COSMISRAYS\fR
+      Task was removed (see CRUTIL)
+
+  \fBNPROTO.FINDGAIN\fR
+      Task was removed (see OBSUTIL)
+
+  \fBNPROTO.OBJMASKS\fR
+      This is a new task for detecting objects in an image and creating
+      an output catalog or pixel mask of found objects.
+
+  \fBTWODSPEC.LONGSLIT.FITCOORDS\fR
+      - Help page describes the contents of the database and how to ext-
+        ernally evaluate the fits.
+      - The RMS is shown in the graph title and in the :show output.
+
+  \fBTWODSPEC.APEXTRACT.APEDIT\fR
+      When there is just one aperture the background regions are shown
+      on the graph without needing to enter the 'b' background mode.
+
+
+\fBIMAGES\fR
+
+  \fBTV.DISPLAY\fR
+      - The mask overlay feature when the displayed image is a reduction of
+        mask (e.g. a block average) now uses the maximum of all mask pixels
+        within the display pixel.
+      - The task will now allow up to 16 frame buffers to be used for the
+	display if allowed by the server. (Currently requires XIMtool V1.3).
+
+  \fBTV.IMEXAMINE\fR
+      - A new key 't' allows output of a region centered on the cursor as an
+        image for further analysis by other programs.
+      - The task will now allow up to 16 frame buffers to be used for the
+	display if allowed by the server. (Currently requires XIMtool V1.3).
+      - Cursor readback will now properly detect the correct image when more
+	than one image is displayed per frame, e.g. in a mosaic.  (Currently
+	requires XIMtool V1.3).
+
+  \fBIMMATCH.IMCOMBINE\fR
+      - New parameters "headers", "bpmasks", "rejmasks",  "nrejmasks", and
+	"expmasks" provide additional types of output.  The old parameters
+	"rejmask" and "plfile" were removed.  The new "nrejmasks" parameter
+	corresponds to the old "plfile" and the new "rejmasks" parameter
+	corresponds to the old "rejmask".
+      - There is a new "combine" type "sum" for summing instead of averaging
+	the final set of offset, scaled, and weighted pixels.
+      - There is a new parameter "outlimits" to allow output of a subregion
+	of the full output.  This is useful for raster surveys with large
+	numbers of images.
+      - Additional keywords may appear in the output headers.
+      - Scaling is now done relative to the first image rather than an average
+	over the images.  This is done so that flux related keywords such as
+	exposure time and airmass remain representative.
+      - A median calculation was made faster.
+      - The previous version is available in the OBSOLETE package.
+
+  \fBIMMATCH.IMCENTROID\fR
+  \fBIMMATCH.IMALIGN\fR
+      A new parameter maxshift has been added to the imcentroid and imalign
+      tasks.  Maxshift defines the maximum permitted difference between the
+      predicted and computed shifts. It is used to reject objects whose
+      positions have wandered too far from the predicted positions.
+
+  \fBIMMATCH.GEOMAP\fR
+  \fBIMCOORDS.CCMAP\fR
+      An iterative rejection capability has been added to the geomap and
+      ccmap tasks. The new parameter maxiter in combination with the existing
+      parameter reject define the rejection parameter. The default value of
+      the reject parameter has been changed from INDEF to 3.0. 
+
+      The colon command ":order <value>" has been added to the geomap and ccmap
+      tasks. The new command enables the user to change all the order parameters
+      simultaneously when experimenting with different fitting functions.
+
+  \fBIMCOORDS.STARFIND\fR
+      The starfind task background estimation algorithm has been modified so
+      that it no longer depends on the value and density of the central pixel.
+
+  \fBIMCOORDS.IMCCTRAN\fR
+      Support for non-zenithal projections has been added to the imcctran task.
+      The previous technique of rotating the cd matrix does not work properly
+      for these functions. The new parameter longpole was added to imcctran.
+      Longpole enables the user to select either the cd matrix or longpole /
+      latpole method for transforming zenithal projections.
+
+  \fBIMCOORDS.CCGET\fR
+      The new task ccget was added to the imcoords package. Ccget extracts
+      objects in a user specified region from a simple text file catalog.
+
+  \fBIMCOORDS.CCSTD\fR
+      The task ccstd was added to the imcoords package. Ccstd transforms pixel
+      and celestial coordinates to standard coordinates and vice versa.
+
+  \fBIMUTIL.HEDIT\fR
+      The new parameter addonly was added to hedit task. The addonly switch
+      is used to add a parameter to the image header only if it does not
+      already exist. The addonly switch has a precedence intermediate between
+      the add and delete switches.
+
+  \fBIMUTIL.IMSTATISTICS\fR
+      An interactive rejection capability has been added to the imstatistics
+      task. The new parameters nclip, lsigma, and usigma define the rejection
+      parameters. A memory cacheing option was also added to imstatistics in
+      order to optionally speed up performance if iterative rejection is en-
+      abled or the midpt/mode is computed.
+
+  \fBIMUTIL.IMEXPR\fR
+      Support for the bitwise operators or (|), and (&), exclusive or (^), and
+      not (~) has been added to the imexpr task. The logical operators or (||)
+      and and (&&) have been made truly logical i.e. they return 0's or 1's,
+      rather than results of a bitwise or and and.
+
+
+\fBPROTO\fR
+  \fBMIMSTATISTICS\fR
+      The new task mimstatistics has been added to the proto package.
+      Mimstatistics does image statistics through a mask.
+
+  \fBRSKYSUB\fR
+      The new task rskysub was added to the proto package. Rskysub does a
+      running mean or median sky subtraction on an ordered list of images
+      using optional background scaling and object masking.
+
+  \fBMSKEXPR\fR
+      The new task mskexpr has been added to the proto package. Mskexpr
+      creates a new mask from a user supplied expression, an optional
+      reference image, and an optional reference mask.
+
+  \fBMSKREGIONS\fR
+      The new task mskregions has been added to the proto package. Mskregions
+      creates a new mask or modifies an existing mask using a list of region
+      definitions or region expressions.
+
+
+\fBXTOOLS\fR
+  \fBSKYWCS\fR
+      A new library skywcs has been added to the xtools package. The skywcs
+      library is a set of routines for managing image and catalog celestial
+      coordinate systems and for transforming from one celestial coordinate
+      system to another.  Skywcs is layered on the Starlink Positional
+      Astronomy library slalib which is installed in the iraf math package.
+
+  \fBCATQUERY\fR
+      A new library catquery was added to the xtools package. The catquery
+      library is a set of routines for doing local and remote catalog and
+      image survey access.
+
+\fBSYSTEM\fR
+  \fBHELP\fR
+      Task was modified to call the XHELP code to run the GUI version of
+      the task if requested.  Task output is the same if the device
+      remains the default 'terminal' value, however resetting the 'device'
+      parameter to one of 'gui', 'html', or 'ps' will either spawn the GUI
+      task under xgterm or print the converted help page to the stdout.
+
+  \fBLROFF\fR
+      The task was enhanced with a new 'format' parameter that allows the
+      text to be formatted as one of: plain-text, HTML, or Postscript. 
+.fi
+
+
+.nh
+Parameter File Changes
+
+In the tables below each parameter change is identified with one of the
+following codes followed by task name and the description of the change.
+.nf
+   * n = new parameter
+   * c = changed/modified parameter
+   * d = deleted parameter
+
+
+\fBCL\fR
+  n cl 			    Added the new CL parameter "release".  This
+			    is a string valued parameter with values such
+			    as "2.11.3a", "2.12", "3.0" etc.  This differs
+			    from "version" which is a descriptive string
+			    such as "NOAO/IRAF V2.11.3 EXPORT".  There can
+			    be multiple releases of one version of the
+			    software, and "release" specifies exactly what
+			    build the software is.  The release strings are
+			    composed in such a way that they can be used
+			    in expressions, e.g. (release >= 2.11.3) would
+			    be true for IRAF V2.11.3 and all subsequent
+			    releases.
+
+\fBDATAIO\fR
+  c dataio.export 	    Made the 'format' parameter automatic mode
+  c dataio.import 	    Made the 'format' parameter automatic mode
+
+\fBIMAGES\fR
+  n imcoords.imcctran 	    Added a new parameter longpole to the imcctran
+			    task. If longpole=yes then coordinate transfor-
+			    mations with zenithal projections will be rot-
+			    ated using longpole rather than the CD matrix.
+
+  c immatch.wregister 	    Fixed boundary option typo, "refect" to "reflect".
+  c immatch.sregister 	    Fixed boundary option typo, "refect" to "reflect".
+
+  n immatch.imcentroid 	    Added a new parameter maxshift to the imcentroid
+    immatch.imalign	    and imalign tasks.  Maxshift is the maximum perm-
+			    itted difference between the computed and predicted
+			    shifts. Maxshift can be used to reject objects whose
+			    centers have wandered too far from the expected
+			    center. By default maxshift is undefined.
+
+  n immatch.geomap 	    Added a new parameter maxiter to the geomap and
+    immatch.ccmap 	    ccmap tasks. Maxiter defines the maximum number of
+			    rejection iterations and has a default value of 0
+			    for no rejection.  
+
+  c immatch.geomap 	    Changed the default value of the ccmap and geomap
+  c immatch.ccmap 	    parameter reject from INDEF to 3.0.
+
+  c immatch.imcombine 	    Numerous changes, see details above
+
+  c imgeom.imlintran	    Changed the nrows argument names to nlines 
+
+
+  n imutil.hedit 	    Added a new addonly parameter to the hedit task. If
+			    addonly is set a new field will only be added to
+			    the image header if it does not already exist.
+
+  n tv.imexamine	    Added new parameters 'output', 'ncoutput', and
+			    'nloutput' used by the new 't' keystroke when
+			    outputting an image section centered on the cursor.
+
+\fBSYSTEM\fR
+  n help 		    New parameters required for GUI options, output
+			    formats for HTML/PS, printer, etc.
+  n lroff		    Added new 'format' parameter for HTML/PS output 
+
+\fBUTILITIES\fR
+
+  c utilities.surfit 	    Added support for the half cross-terms option to
+			    the surfit task.  This involved changing the type
+			    of the xterms parameter from boolean (yes/no) to
+			    string (none,half,full).
+
+\fBNOAO\fR
+
+  \fBASTUTIL\fR
+    n astutil.setairmass    new parameters ra, dec, equinox, st, ut, scale
+
+  \fBDIGIPHOT\fR
+    n apphot 		    new package parameters wcsin, wcsout, and cache
+    n apphot.center 	    new parameters wcsin, wcsout, cache
+    n apphot.daofind 	    new parameters wcsout, cache
+    n apphot.fitpsf 	    new parameters wcsin, wcsout, cache
+    n apphot.fitsky 	    new parameters wcsin, wcsout, cache
+    n apphot.phot 	    new parameters wcsin, wcsout, cache
+    n apphot.polymark 	    new parameters wcsin, wcsout, cache
+    n apphot.polyphot 	    new parameters wcsin, wcsout, cache
+    n apphot.qphot 	    new parameters wcsin, wcsout, cache
+    n apphot.radprof 	    new parameters wcsin, wcsout, cache
+    n apphot.wphot 	    new parameters wcsin, wcsout, cache
+
+    n daophot 		    new package params wcsin, wcsout, wcspsf, and cache
+    n daophot.addstar 	    new parameters wcsin, wcsout, wcspsf, and cache
+    n daophot.allstar 	    new parameters wcsin, wcsout, and wcspsf
+    n daophot.daoedit 	    new parameters cache
+    n daophot.daofind 	    new parameters wcsout, and cache
+    n daophot.group 	    new parameters wcsin, wcsout, wcspsf, and cache
+    n daophot.nstar 	    new parameters wcsin, wcsout, wcspsf, and cache
+    n daophot.peak 	    new parameters wcsin, wcsout, wcspsf, and cache
+    n daophot.phot 	    new parameters wcsin, wcsout, and cache
+    n daophot.psf 	    new parameters wcsin, wcsout, and cache
+    n daophot.substar 	    new parameters wcsin, wcsout, and cache
+
+
+  \fBONEDSPEC\fR
+    n standard		    new parameter mag, magband, and teff.  These 
+    n splot		    params can be use to specify calibration files
+    n lcalib	            as blackbody curves scale to a specified magnitude
+
+  \fBTWODSPEC\fR
+    c apextract.apall1	    Reduced the 'polysep' parameter.
+    c apextract.apdebug	    Reduced the 'polysep' parameter.
+    c apextract.apfit1	    Reduced the 'polysep' parameter.
+    c apextract.apnoise1    Reduced the 'polysep' parameter.
+    c apextract.apnorm1	    Reduced the 'polysep' parameter.
+    c apextract.apparams    Reduced the 'polysep' parameter.
+.fi
+
+
+
+.nh
+Details of Major System Changes
+
+.nh 2
+FITS kernel changes
+.nf
+        The FITS kernel was modified to add support for storing images in
+    extensions as compressed pixel masks.  The mask is stored as a binary
+    table using the "ZIMAGE" (compressed image) convention proposed by White,
+    Greenfield, Pence, and Tody in 1999:
+
+            http://heasarc.gsfc.nasa.gov
+            /docs/software/fitsio/compression/compress_image.html
+
+        In the current implementation only the "PLIO_1" compression
+    algorithm is implemented.  Mask extensions may be read or written directly
+    by the kernel.  When writing a new extension it will be appended to the
+    MEF file.  To append an image to a MEF file as a mask, include "type=mask"
+    in the image kernel section when the output image is opened.
+
+        Masks are interfaced to the system as images and may be read and
+    written like any other image via IMIO.  They have a normal image header
+    and can be manipulated with any program that deals with images.  The pixel
+    type is INT.
+
+        It is also possible to access a mask image as a PLIO mask.  An
+    IMSTATI query for IM_PLDES parameter will return the PLIO mask descriptor.
+    While a mask extension is opened under IMIO it is represented as a PLIO
+    mask and may be accessed in this form like any other mask.
+
+        The mask image is stored in the FITS binary table (BINTABLE)
+    extension when the image is closed, and is loaded from the extension when
+    the image is opened.  The compression representation used to store the
+    mask in the binary table is the same as is used within PLIO.  The new
+    (V2.12) encoding is used, allowing very large masks to be stored.
+    Currently masks up to 3D are supported.  Data on each 2D mask plane
+    will be compressed in both X and Y as with PLIO.  The depth of the mask
+    is preserved.
+
+        Although a mask is stored as a binary table the format of the
+    table is not completely general.  In the current implementation there
+    can be only one column in the table (COMPRESSED_DATA).  This is an
+    integer-valued variable length array column containing, for each line of
+    the N-dimensional image, the PLIO compressed version of that image line.
+    The actual compressed data is stored in the heap area of the table.
+    Multiple image lines may point to the same compressed line list, e.g.,
+    to store the empty line or to compression in Y.
+.fi
+
+
+.nh 2
+Large Image Support
+
+	The following changes were made to enable IMIO to use larger buffer
+sizes to optimize i/o for large images:
+
+.nf
+        The default file buffer size set by IMIO is unchanged: it is still
+    about 512 MB, the value set for V2.11.2.  However, a new parameter
+    IM_BUFFRAC was added.  Both IM_BUFSIZE and IM_BUFFRAC are used to help
+    determine the FIO buffer size set when an image is opened.  The logic
+    for this is implemented in imsetbuf.x.
+
+        Backwards compatibility.  If you do nothing about IMIO/FIO buffers
+    in your program, the system may transparently use a larger buffer for
+    larger images.  If you set BUFSIZE in your program, the system will
+    by default use the value you give, or possibly a larger value, if the
+    image you are accessing is very large.  If you set BUFSIZE and you want
+    to guarantee that the value you set is used (even for very large images)
+    then you should also set BUFFRAC=0 to ensure that only BUFSIZE is used.
+
+        How it works.  BUFFRAC specifies the default FIO buffer size used to
+    access an image, expressed as a percentage of the size of the image.
+    For example, the builtin default value of BUFFRAC=10 will try to make a
+    FIO buffer 10% of the size of the image.  The actual value used will be
+    given by BUFFRAC, but will be at least BUFSIZE, and no more than a builtin
+    default maximum value, currently 32 MB.  Given the builtin defaults,
+    the buffer size will range from 0.5 to 32 MB depending upon the size of
+    the image being accessed.  As noted above, BUFSIZE and BUFFRAC can be
+    set to force the buffer size to a specific value if desired.
+
+        Environment variables for both parameters are provided.  The names
+    are "IMIO_BUFSIZE" (specified as bytes) and "IMIO_BUFFRAC" (specified
+    as a decimal fraction).  If defined, these override (at image open time)
+    the builtin default values for both parameters.  An IMSET call by the
+    application will override all such defaults.
+
+        The FIO buffer allocated will not be larger than the size of the
+    image.  The FIO buffer will also not exceed the maximum size set by
+    the file driver being accessed.  For example, for PLIO images the file
+    buffer will not exceed about 2KB, even for a very large mask.  This is
+    because the "pixel file" for a PLIO image is dev$null, the driver for
+    which specifies a maximum i/o buffer size of 2K (the real file to load
+    or save the mask will use a different descriptor).
+
+        The intent here is to provide an adaptive mechanism for setting the
+    FIO buffer size used to access an image, which automatically adapts to
+    the size of the image being accessed.  If you access a lot of small
+    images you will get smaller buffers - everything will be as before.
+    If you access very large images, you may get large buffers up to the
+    builtin maximum value of (currently) 32 MB.
+
+        Using large buffers could cause a machine to run out of memory.
+    However, it is likely that if someone is working on 300 MB images
+    that they are using a machine which has a memory at least that large
+    - probably larger.  If there are problems, the environment variable
+    overrides can be used to tune IMIO.
+
+        The reason for large file buffers is to limit the number of disk
+    data transfers, and hence the number of disk seeks.  Using buffers larger
+    than a certain amount (32 MB is generous) is probably counterproductive.
+    If the i/o system provides 20 MB/sec i/o transfers, 32 MB will take
+    1.6 seconds.  This should be more than a large enough granularity to
+    provide efficient i/o, hence is a reasonable limit (at this point paging
+    effects are likely to dominate).
+.fi
+
+.nh 2
+Virtual Memory Cache
+
+	The VMcache client interface and daemon provide a method by which
+data-intensive IRAF tasks (or non-IRAF tasks for that matter) can manage
+how files/images are maintained in virtual memory to avoid excessive system
+paging.  In essence it's a way to "lock" a specific image in memory to
+improve performance.  As of this release no tasks in the system have been
+modified to make use of the VMcache daemon, however installing it in the
+system at this point provides a framework for future applications and
+systems development.
+
+	The following notes summarize the changes made for this feature
+and describe it's function in more detail.  A more complete description of
+the interface, environment variables which control it, etc can be found in
+the main systems revisions file iraf$local/notes.v211.
+
+.nf
+	The source for the developmental version of the VMcache library
+    and the VMcache daemon (vmcached) have been installed in the
+    unix$boot tree and the HSI binary file driver was modified to add VMcache
+    client support.  This adds two new capabilities to the driver: 1)
+    built-in support for direct i/o (on systems that support it), and 2)
+    a client interface to the VMcache daemon to permit the daemon to
+    optimally manage binary file i/o if a VMcache daemon is present.
+
+    The vmcached code is complete but only enough debug/testing was done to
+    support development of the VMcache client interface for IRAF (the vmcached
+    code is debugged but the new version of the vmcache library code has
+    not been tested).  Since the daemon can be utilized outside the normal
+    IRAF release we do not have to fully develop it for the release.
+
+    It should be stressed that VMcache is only useful or warranted for
+    systems that are very data intensive.  The standard host operating
+    system file access heuristics are best for "normal" processing where
+    either the system is not really busy, or the datafiles are not
+    excessively large.  On systems with very large physical memories
+    where massive amounts of data are being processed, VMcache can make
+    a significant difference in overall system performance.
+
+    VMcache is too complex to document here.  Without going into the
+    details, its function is to manage a cache of files in system
+    virtual memory.  Files can be explicitly cached or uncached, or they
+    can be "accessed", and VMcache will decide whether or not to cache
+    the file in virtual memory.  This is what the VMcache client
+    interface does: every time it accesses (opens or extends) a file
+    larger then the VM threshold it sends an "access" directive to the
+    VMcache daemon.  The daemon sends back a response of 0 (file not
+    cached; use direct i/o to access the file), or 1 (file cached in VM;
+    use normal VM-buffered i/o to access the file).  Even if a file is
+    not cached the daemon keeps track of all accesses.  Files which are
+    frequently accessed will have a higher priority and are more likely
+    to be cached in memory.
+
+    The VMcache daemon is a separate system-level program outside of
+    IRAF.  This is necessary to provide a central system-wide cache
+    controller.  It also provides flexibility, allowing multiple
+    versions of the daemon to exist, e.g., to allow experimentation with
+    different types of caching algorithms.  It also allows easy
+    customization of the daemon independently of the IRAF applications
+    using the VMcache client interface.
+.fi
+
+
+.nh 2
+New Developer Libraries
+
+.nf
+    o Several new libraries are now available for developers:
+
+      \fBPSIO\fR	New Postscript text generation library installed in the
+		sys$psio.  The PSIO interface is used to format a block of
+		text as Postscript output on a page of a given size (Letter,
+		Legal, A4 or B5).  See the psio$README file for details.
+
+      \fBCATQUERY\fR	Remote astrometric/photometric catalog access lib installed
+		in the XTOOLS utility library.  
+		  The catquery package provides a set of routines for local
+		and remote catalog and image survey server access.  The sup-
+		ported catalogs and image surveys are described in records
+		stored in a catalog and image survey configuration file
+		respectively. The catalog and image survey records specify
+		the network address, the query format, and the output format
+		for each supported catalog or image display server.  See
+		"help catalogs" and "help surveys" for details.
+
+      \fBSKYWCS\fR	Sky coordinate transformation library installed in the XTOOLS
+		utility library.
+		  The skywcs package contains a simple set of routines for
+		managing sky coordinate information and for transforming from
+		one sky coordinate system to another. The sky coordinate
+		system is defined either by a system name, e.g.  "J2000",
+		"galactic", etc., or by an image system name, e.g. "dev$ypix"
+		or "dev$ypix world".
+.fi
+
+
+.nh 
+System Changes Which May Affect You
+
+.nf
+   * \fBSHARED LIBRARY VERSION INCREMENTED\fR (Sun/IRAF only)
+	The IRAF shared library for SunOS and Solaris platforms has been
+	incremented with this release due to the nature of various system
+	changes.  Existing IRAF binaries (e.g. locally written software
+	or external packages) will continue to run using the old shared 
+	image, however they will need to be recompiled against V2.12 in order
+	to pick up the numerous system bug fixes and features in this release.
+	In particular, pixel masks produced by V2.12 IRAF tasks may be 
+	incompatible with external packages which have not been recompiled.
+
+   * \fBEXTERNAL PACKAGE RECOMPILATION\fR
+	The V2.12 release contains changes to the FIO and PLIO/PMIO interface
+	header files used by numerous applications.  Relinking of an external
+	package may fail to pick up these changes and not recompile a source
+	file which uses one of these header files if the mkpkg file doesn't
+	correctly list all of the dependencies (nearly all packages have one
+	or more mkpkg files which have this problem).  In the worst cases 
+	this could lead to a runtime error due to the incompatibilities.
+
+	For this reason we recommend that all packages and local tasks be
+	recompiled (completely from source* (rather than simply relinked
+	against the new version) to assure that all changes and new features
+	will be included.  Recompilation also guarantees that packages can
+	take advantage of some of the larger buffer sizes and optimizations
+	in this release.  Site support can supply a list of missing mkpkg
+	dependencies for most external packages being developed outside NOAO
+	that wish to fix these files for a future release.  
+
+   * \fBPARAMETER FILE CHANGES\fR
+	As with all major releases, we recommend that you do a MKIRAF and
+	delete all your old parameter files after the IRAF upgrade. You may
+	choose not to do this if you are in the midst of a project and have
+	setups that may be difficult to reproduce. 
+
+	The automatic parameter file update/merge mechanism, which is used
+	if you do not initialize your parameters with MKIRAF, is based on
+	file date comparisons.  If you run IRAF V2.11 after V2.12 has been
+	installed, the file dates on your uparm parameter files will be
+	more recent than the V2.12 installation date.  If you then try to
+	run V2.12, the automatic parameter file merge/update will fail due
+	to the file dates.  The system only updates personal parameter
+	files which are older than the update date of the system.  A
+	MKIRAF avoids the problem if you delete your parameter files,
+	causing them to be updated from the system default versions.
+
+   * \fBINSTALLATION SCRIPT CHANGES\fR
+	As the first step of an ongoing effort to simplify the installation
+	and system configuration, the IRAF install script was rewritten to
+	do some error-checking of the iraf setup, present a simplified and
+	easier to read output, and do some common post-install configuration
+	of the system.  Additionally, the SYSINFO diagnostic script for
+	finding system errors and reporting on the configuration, and a new
+	UNINSTALL script for removing IRAF files/links from the system have
+	also been installed.  The old install script is still available as
+	a fallback in case problems with the new script are found.
+
+   * \fBHELP SYSTEM CHANGES\fR
+	The HELP task was modified with several new parameters controlling
+	the display and formatting of the help pages.  Help may now be
+	presented as formatted text (as before), HTML, or fully formatted
+	Postscript.  Additionally, users running under an XGterm window can
+	use the task in a new GUI mode.  The help GUI allows users to browse
+	the help system and easily search for tasks/topics using a familiar
+	web-like interface.  The GUI mode is not the default, but can be
+	enabled easily using the 'device' parameter.
+
+   * \fBIMAGE DISPLAY CHANGES\fR
+	Tasks which display images or interact with the image display were
+	modified to take advantage of new features added to XImtool V1.3
+	(e.g. the multiple WCS and pixel-value readouts and 16 display frame
+	buffers).  These changes were done in a backwards compatible way so
+	interaction with display servers such as SAOimage, SAOtng, DS9, or
+	older XImtool versions should be unaffected.  If problems are dis-
+	covered a CL environment variable 'disable_wcs_maps' can be defined
+	to force all of the old behaviors.  These changes do not add any new
+	functionality to the tasks themselves, only the underlying display
+	protocols.
+
+  * \fBPLIO Changes\fR
+        The LEN and BLEN fields of the encoded line list (LL) descriptor
+        would limit the length of a pixel area (and hence the size of a
+        pixel mask) to the max size of a signed short, 32768.  This was due
+        to the use of a simple array of type short to encode the line list
+        (which simplifies handling considerably).  Nonetheless the limit to
+        32K was unacceptable.  The fix adopted was to increase the LL header
+        from 3 to 7 words.  Two 16 bit words are now used to encode each of
+        LEN and BLEN.  A "version" word was added to allow the old, new, and
+        future encodings to be distinguished.  A "hdrlen" word was added to
+        parameterize the length of the LL header, rather than fix it at
+        compile time as in the initial version.  With this change, the
+        maximum length of an image line under PLIO is increased from 32768
+        to 1073741824 (32768*32768).  All the higher level PLIO code is
+        integer, so should already support larger masks.
+
+        This was done in such a way that old line lists can still be read,
+        although PLIO will always write out new format line lists (pixel
+        mask files and images, QPOE, and MWCS all store encoded line lists
+        in external storage, so backwards compatibility is important; also
+        existing complied programs will continue to generate the old
+        format).  The cost is 8 bytes per encoded line list.  For most masks
+        this should only increase the size of the mask by a few percent at
+        most.
+
+   * \fBNEW ENVIRONMENT VARIABLES\fR
+	The following new environment variables may be defined to tune the
+	size of the system file i/o buffers used by the image i/o system.
+	The system will automatically adjust to use larger buffers when
+	accessing larger images, these variables may be set to further
+	optimize the buffers
+
+	  \fBIMIO_BUFSIZE\fR      Size of the FIO buffer size in bytes.
+
+	  \fBIMIO_BUFFRAC\fR      FIO buffer size expressed as a percentage of 
+			    the image size.  Actual value will be at least
+			    BUFSIZE and no more than BUFMAX.
+
+	  \fBIMIO_BUFMAX\fR	    Max size of FIO buffer which will override the
+			    32Mb default.
+
+
+	Other miscellaneous environment variables:
+
+	  \fBdisable_wcs_maps\fR  If defined or set to 'yes', this variable will
+			    force any tasks which interact with the image
+			    display to use the old protocols.
+
+	  \fBpspage\fR 	    Variable which is used by the PSIO interface to
+			    set the default page size.  Acceptable values
+			    include "letter" (the default) for US Letter,
+			    "legal" for US Legal, and "a4" and "b5" for the
+			    most common European sizes.  Pspage can be used
+		 	    by the new HELP and LROFF tasks to automatically
+			    set the desired Postscript page size. 
+.fi
+
+.endhelp