1 files changed, 6 insertions, 0 deletions
diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml
index 0e1be153c7..48f273b0b2 100644
--- a/docs/sample_config.yaml
+++ b/docs/sample_config.yaml
@@ -643,6 +643,12 @@ caches:
    # takes priority over setting through the config file.
    # Ex. SYNAPSE_CACHE_FACTOR_GET_USERS_WHO_SHARE_ROOM_WITH_USER=2.0
    #
+   # Some caches have '*' and other characters that are not
+   # alphanumeric or underscores. These caches can be named with or
+   # without the special characters stripped. For example, to specify
+   # the cache factor for `*stateGroupCache*` via an environment
+   # variable would be `SYNAPSE_CACHE_FACTOR_STATEGROUPCACHE=2`.
+   #
    per_cache_factors:
      #get_users_who_share_room_with_user: 2.0