diff --git a/doc/developer-guidelines.sgml b/doc/developer-guidelines.sgml
index e7754f4e..d7b7a773 100644
--- a/doc/developer-guidelines.sgml
+++ b/doc/developer-guidelines.sgml
@@ -269,10 +269,6 @@
@10:20
≥ 10 and ≤ 20, (inside the range of {10 .. 20})
-
- 10
- < 0 or > 10, (outside the range of {0 .. 10})
-