Index: tests/array-collections/dimexpr-match-detail.sh
===================================================================
--- tests/array-collections/dimexpr-match-detail.sh	(revision 829821c468be4f6d1bc7cd0065241c9c9f738b87)
+++ tests/array-collections/dimexpr-match-detail.sh	(revision 090b07639c6b027e4addfbac740d04f8a642ae58)
@@ -2,4 +2,11 @@
 # This script helps you run the dimexpr-match test manually, in a more thorough fashion.
 # test.py runs do not use this script.
+
+# When a test.py run shows that an output has changed, use this script for verification, before running --regenerate-expected.
+# Particularly with -ERRS, we don't actually care what the error message is (likely source of noise requiring --regenerate-expected), just that all the should-reject cases are rejected (which this script shows).
+
+# Success means the script does not print "TEST FAILURE."
+# Expect one large output with a mix of "done" and "skip" messages.  That is the acceptance cases.
+# Then expect many small outputs all showing rc=1.  These are the rejection cases.
 
 # The thoroughness that this script affords is
@@ -8,9 +15,10 @@
 #   - observing the behaviour of a compiler other than the CFACC version in whose folder the test occurs; for example, GCC
 
-# usage (one of)
-#   ./dimexpr-match-detail.sh '/u0/mlbrooks/cfa2/build-straw3/driver/cfa -DCFA_PREVIEW_FUNCTIONALITY'
+# usage examples
+#   ./dimexpr-match-detail.sh cfa
+#   ./dimexpr-match-detail.sh      # same as above
 #   ./dimexpr-match-detail.sh ~/cfa6/build/driver/cfa
+#   ./dimexpr-match-detail.sh "$cfa -m32 -nodebug"
 #   ./dimexpr-match-detail.sh 'gcc -x c'
-
 
 
Index: tests/array-collections/dimexpr-match.hfa
===================================================================
--- tests/array-collections/dimexpr-match.hfa	(revision 829821c468be4f6d1bc7cd0065241c9c9f738b87)
+++ tests/array-collections/dimexpr-match.hfa	(revision 090b07639c6b027e4addfbac740d04f8a642ae58)
@@ -2,4 +2,6 @@
 
 //  Framework for the dimexpr-match tests.
+//
+//  For general test-suite maintenance instrutions, see *-detail.sh.
 //
 //  These tests show whether an expression of type like `float (*)[25]`
@@ -181,5 +183,5 @@
     - reject STA/non-STA crossing
 
-CFA rules ("preview" only)
+CFA rules
     - accept a pair from group STA if it has the same value
     - accept a pair from group DYN if it is written out the same (e.g. refers to same variable)