diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines
index c4cb5ff..48aa4ed 100644
--- a/Documentation/CodingGuidelines
+++ b/Documentation/CodingGuidelines
@@ -386,6 +386,11 @@
  - Use Git's gettext wrappers to make the user interface
    translatable. See "Marking strings for translation" in po/README.
 
+ - Variables and functions local to a given source file should be marked
+   with "static". Variables that are visible to other source files
+   must be declared with "extern" in header files. However, function
+   declarations should not use "extern", as that is already the default.
+
 For Perl programs:
 
  - Most of the C guidelines above apply.