diff --git a/README.md b/README.md
index 4e38b5f..26d0e53 100644
--- a/README.md
+++ b/README.md
@@ -79,6 +79,27 @@ decided to pass on those five; they simply do not apply to the chosen database.
 `SKIP_` is the other thing: a test that does apply and is being passed over, which
 is worth reporting as such.
 
+A third pair asks about the BINARY rather than the run:
+
+```
+# REQUIRE_FEATURE: A B          the test applies only if the build has ALL of them
+# SKIP_FEATURE:    A B          the test applies only if the build has NONE of them
+```
+
+Separate from `REQUIRE_<TAG>` because it is a different question with different
+matching. `REQUIRE_<TAG>` holds ONE current value and asks whether it is among
+the listed alternatives, so `REQUIRE_DB: corDB mongoc` means "either". A feature
+list is a SET, and `REQUIRE_FEATURE: A B` means a test that needs both — the
+opposite reading. `SKIP_FEATURE` is the direction a reduced build needs: a test
+asserting the 501 for an endpoint compiled out can only run where it is out.
+Both drop the test from the run list rather than reporting it skipped.
+
+The set comes from `COR_TEST_FEATURES`, space-separated, which the repo's
+`corTestParams.sh` sets — normally by asking the binary what it was built with.
+UNSET means the repo does not report features, and then both markers are inert
+and every test runs: a broken detection fails loudly instead of silently
+skipping the suite.
+
 `--INIT--`, `--RUN--` and `--TEARDOWN--` are executed with `bash`, so they can use
 shell freely — and any helper functions the repo exposes (see below).
 
@@ -97,6 +118,12 @@ Content-Length: REGEX(\d+)
 "id": "REGEX(urn:ngsi-ld:.+)"
 ```
 
+⚠️ The pattern is spliced into the line's pattern UNBRACKETED, so a top-level
+`|` alternates the whole line, not the parenthesised part: `x: REGEX(true|false)`
+becomes `x:\ true|false`, which matches `x: true` and then demands that `false`
+start at column 1. It accepts one branch and rejects the other while looking
+correct. Write a pattern without top-level alternation (`REGEX([a-z]+)`).
+
 **`#SORT_START` / `#SORT_END`** — the lines between the markers are compared
 order-independently, for output whose ordering isn't guaranteed:
 
diff --git a/corTest b/corTest
index 5f0d806..a97e4eb 100755
--- a/corTest
+++ b/corTest
@@ -416,6 +416,78 @@ function reportSkip()
 }
 
 
+# -----------------------------------------------------------------------------
+#
+# featureOn - is <feature> compiled into the binary under test?
+#
+function featureOn()
+{
+  case " $COR_TEST_FEATURES " in
+    *" $1 "*) return 0 ;;
+  esac
+  return 1
+}
+
+
+# -----------------------------------------------------------------------------
+#
+# featureApplies - does this test case apply to the BUILD under test?
+#
+#   # REQUIRE_FEATURE: A B ...   (the test applies only if the build has ALL of them)
+#   # SKIP_FEATURE:    A B ...   (the test applies only if the build has NONE of them)
+#
+# A separate question from REQUIRE_<TAG> above, and so a separate mechanism.
+# REQUIRE_<TAG> asks "is the run configured this way", and matches ONE current
+# value against a list of alternatives. This asks "does the binary contain that
+# code at all", and matches against a SET - every name in the list has to be in
+# it. Feeding features through the value-matching arrays would have made
+# "REQUIRE_FEATURE: A B" mean "A or B", which is the opposite of what a test
+# needing both features means.
+#
+# SKIP_FEATURE is the direction a compiled-out build needs: a test that asserts
+# the 501 for an endpoint that is not in the build can only run where the
+# endpoint is not in the build.
+#
+# COR_TEST_FEATURES holds the ON features, space separated - the repo's
+# corTestParams.sh sets it, normally by asking the binary. UNSET means the repo
+# does not report a feature set, and then both markers are inert: every test
+# runs. That is the loud failure rather than the quiet one - a suite that
+# silently skipped everything on a broken detection would look green.
+#
+# Returns 0 if the test applies, 1 if it does not (sets NA_REASON).
+#
+function featureApplies()
+{
+  local testFile="$1"
+  local line
+  local f
+
+  if [ -z "${COR_TEST_FEATURES+set}" ]; then return 0; fi
+
+  line=$(grep "^# *REQUIRE_FEATURE:" "$testFile" 2>/dev/null | head -1)
+  if [ -n "$line" ]; then
+    for f in ${line#*:}; do
+      if ! featureOn "$f"; then
+        NA_REASON="build has no $f"
+        return 1
+      fi
+    done
+  fi
+
+  line=$(grep "^# *SKIP_FEATURE:" "$testFile" 2>/dev/null | head -1)
+  if [ -n "$line" ]; then
+    for f in ${line#*:}; do
+      if featureOn "$f"; then
+        NA_REASON="build has $f"
+        return 1
+      fi
+    done
+  fi
+
+  return 0
+}
+
+
 # -----------------------------------------------------------------------------
 #
 # testApplies - does this test case apply to the configuration being run?
@@ -436,6 +508,8 @@ function testApplies()
   local testFile="$1"
   NA_REASON=""
 
+  if ! featureApplies "$testFile"; then return 1; fi
+
   for ix in "${!COR_CLI_PARAM_TAGS[@]}"; do
     local tag="${COR_CLI_PARAM_TAGS[$ix]}"
     if [ -z "$tag" ]; then continue; fi