diff --git a/docs/Command_Templates.md b/docs/Command_Templates.md
index 1aa85d31..7a0bc34d 100644
--- a/docs/Command_Templates.md
+++ b/docs/Command_Templates.md
@@ -5,7 +5,9 @@ sequences in gcode_macro (and similar) config sections.
 
 Case is not important for the G-Code macro name - MY_MACRO and
 my_macro will evaluate the same and may be called in either upper or
-lower case.
+lower case. If any numbers are used in the macro name then they must
+all be at the end of the name (eg, TEST_MACRO25 is valid, but
+MACRO25_TEST3 is not).
 
 ### Formatting of G-Code in the config