--- a/mercurial/templatefuncs.py	Wed Feb 14 22:55:11 2024 -0500
+++ b/mercurial/templatefuncs.py	Wed Feb 14 15:21:44 2024 -0500
@@ -439,9 +439,10 @@
 
 @templatefunc(b'label(label, expr)', requires={b'ui'})
 def label(context, mapping, args):
-    """Apply a label to generated content. Content with
-    a label applied can result in additional post-processing, such as
-    automatic colorization."""
+    """Apply a label to generated content. Content with a label
+    applied can result in additional post-processing, such as
+    automatic colorization. In order to receive effects, labels must
+    have a dot, such as `log.secret` or `branch.active`."""
     if len(args) != 2:
         # i18n: "label" is a keyword
         raise error.ParseError(_(b"label expects two arguments"))