diff --git a/README_maintainers.md b/README_maintainers.md
index 42c02a9a94..1236a60862 100644
--- a/README_maintainers.md
+++ b/README_maintainers.md
@@ -213,8 +213,9 @@ These tests produce a certain thread on infrastructure or the test system, and t
 -----
 These tests are currently listed as "grey", which means that they are
 known to be unstable or broken. These tests will not be executed by the
-testing framework if the option `--skipGrey` is given. See
-`tests/Greylist.txt` for up-to-date information about greylisted tests.
+testing framework if the option `--skipGrey` is given. If `--onlyGrey`
+option is given then non-"grey" tests are skipped. See `tests/Greylist.txt`
+for up-to-date information about greylisted tests.
 Please help to keep this file up to date.
 
 Test frameworks used