Index: trunk/Ohana/src/opihi/dvo/avextract.c
===================================================================
--- trunk/Ohana/src/opihi/dvo/avextract.c	(revision 20936)
+++ trunk/Ohana/src/opihi/dvo/avextract.c	(revision 21086)
@@ -183,31 +183,31 @@
   if ((argc > N + 1) && !strcasecmp (argv[N+1], "fields")) {
     gprint (GP_ERR, " USAGE: avextract field[,field,field...] where (expression)\n");
-    gprint (GP_ERR, "  RA : right ascension (J2000)\n");
-    gprint (GP_ERR, "  DEC : declination \n");
-    gprint (GP_ERR, "  dRA : ra scatter \n");
-    gprint (GP_ERR, "  dDEC : dec scatter\n");
-    gprint (GP_ERR, "  uRA : proper motion in ra\n");
-    gprint (GP_ERR, "  uDEC : proper motion in dec\n");
-    gprint (GP_ERR, "  duRA : proper motion error in ra\n");
-    gprint (GP_ERR, "  duDEC : proper motion error in dec\n");
+    gprint (GP_ERR, "  RA : right ascension (J2000) [degrees]\n");
+    gprint (GP_ERR, "  DEC : declination [degrees]\n");
+    gprint (GP_ERR, "  dRA : ra scatter [degrees]\n");
+    gprint (GP_ERR, "  dDEC : dec scatter [degrees]\n");
+    gprint (GP_ERR, "  uRA : proper motion in ra [arcseconds]\n");
+    gprint (GP_ERR, "  uDEC : proper motion in dec [arcseconds]\n");
+    gprint (GP_ERR, "  duRA : proper motion error in ra [arcseconds]\n");
+    gprint (GP_ERR, "  duDEC : proper motion error in dec [arcseconds]\n");
     gprint (GP_ERR, "  PAR : parallax\n");
     gprint (GP_ERR, "  dPAR : parallax error \n");
     gprint (GP_ERR, "  nmeas : number of measurements\n");
     gprint (GP_ERR, "  nmiss : number of non-detections\n");
-    gprint (GP_ERR, "  xp : positional chi-square\n");
+    gprint (GP_ERR, "  xp : positional raw chi-square\n");
     gprint (GP_ERR, "  flag : object flags\n");
-    gprint (GP_ERR, "  photocode:ave : average magnitude for photcode\n");
-    gprint (GP_ERR, "  photocode:ref : reference magnitude system for photcode\n");
-    gprint (GP_ERR, "  photocode:inst : first instrumental magnitude for photcode\n");
-    gprint (GP_ERR, "  photocode:cat : first catalog magnitude for photcode\n");
-    gprint (GP_ERR, "  photocode:sys : first system magnitude for photcode\n");
-    gprint (GP_ERR, "  photocode:rel : first relative magnitude for photcode\n");
-    gprint (GP_ERR, "  photocode:cal : first calibrated magnitude for photcode \n");
-    gprint (GP_ERR, "  photcode:err : magnitude error for photcode\n");
-    gprint (GP_ERR, "  photcode:chipsq : chi-square of magnitude fit\n");
+    gprint (GP_ERR, "  <photcode>:ave : average magnitude for <photcode>\n");
+    gprint (GP_ERR, "  <photcode>:ref : reference magnitude system for <photcode>\n");
+    gprint (GP_ERR, "  <photcode>:inst : first instrumental magnitude for <photcode>\n");
+    gprint (GP_ERR, "  <photcode>:cat : first catalog magnitude for <photcode>\n");
+    gprint (GP_ERR, "  <photcode>:sys : first system magnitude for <photcode>\n");
+    gprint (GP_ERR, "  <photcode>:rel : first relative magnitude for <photcode>\n");
+    gprint (GP_ERR, "  <photcode>:cal : first calibrated magnitude for <photcode> \n");
+    gprint (GP_ERR, "  <photcode>:err : magnitude error for photcode\n");
+    gprint (GP_ERR, "  <photcode>:chipsq : chi-square of magnitude fit\n");
     gprint (GP_ERR, "  type : dophot type (unused)\n");
     gprint (GP_ERR, "  typefrac : dophot type fraction (unused)\n");
-    gprint (GP_ERR, "  photcode:ncode : number of measurements in photcode \n");
-    gprint (GP_ERR, "  photcode:nphot : number of measurements used for photcode average\n");
+    gprint (GP_ERR, "  <photcode>:ncode : number of measurements in photcode \n");
+    gprint (GP_ERR, "  <photcode>:nphot : number of measurements used for photcode average\n");
     return (FALSE);
   }