diff --git a/doc/classes/String.xml b/doc/classes/String.xml
index 1e2dfacd4aa..2d1b975729e 100644
--- a/doc/classes/String.xml
+++ b/doc/classes/String.xml
@@ -523,14 +523,14 @@
 			<return type="bool" />
 			<argument index="0" name="expr" type="String" />
 			<description>
-				Does a simple case-sensitive expression match, where [code]"*"[/code] matches zero or more arbitrary characters and [code]"?"[/code] matches any single character except a period ([code]"."[/code]).
+				Does a simple case-sensitive expression match, where [code]"*"[/code] matches zero or more arbitrary characters and [code]"?"[/code] matches any single character except a period ([code]"."[/code]). An empty string or empty expression always evaluates to [code]false[/code].
 			</description>
 		</method>
 		<method name="matchn">
 			<return type="bool" />
 			<argument index="0" name="expr" type="String" />
 			<description>
-				Does a simple case-insensitive expression match, where [code]"*"[/code] matches zero or more arbitrary characters and [code]"?"[/code] matches any single character except a period ([code]"."[/code]).
+				Does a simple case-insensitive expression match, where [code]"*"[/code] matches zero or more arbitrary characters and [code]"?"[/code] matches any single character except a period ([code]"."[/code]). An empty string or empty expression always evaluates to [code]false[/code].
 			</description>
 		</method>
 		<method name="md5_buffer">