Config guide: Explain how to use different code owner configs in a fork

Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: I5f1b6d0d2644a8edfcfdf3690c35abbeba270795
diff --git a/resources/Documentation/config-guide.md b/resources/Documentation/config-guide.md
index d59120a..8a55a6c 100644
--- a/resources/Documentation/config-guide.md
+++ b/resources/Documentation/config-guide.md
@@ -154,6 +154,17 @@
 Config Files In Revision](rest-api.html#check-code-owner-config-files-in-revision)
 REST endpoint.
 
+## <a id="differentCodeOwnerConfigurations">Use different code owner configurations in a fork
+
+If a respository is forked and code owners are used in the original repository,
+the code owner configuration of the original repository shouldn't apply for the
+fork (the fork should have different code owners, and if the fork is stored on
+another Gerrit host it's also likely that the original code owners cannot be
+resolved on that host). In this case it is possible to [configure a file
+extension](config.html#pluginCodeOwnersFileExtension) for code owner config
+files in the fork so that its code owner config files do not clash with the
+original code owner config files.
+
 ## <a id="securityPitfalls">Security pitfalls
 
 While requiring code owner approvals is primarily considered as a code quality
diff --git a/resources/Documentation/config.md b/resources/Documentation/config.md
index 1b972db..9c85ca5 100644
--- a/resources/Documentation/config.md
+++ b/resources/Documentation/config.md
@@ -58,11 +58,11 @@
 
 <a id="pluginCodeOwnersFileExtension">plugin.@PLUGIN@.fileExtension</a>
 :       The file extension that should be used for code owner config files.\
-        Allows to use different owner configurations for upstream and internal
-        in the same repository. E.g. if upstream uses `OWNERS` code owner config
-        files (no file extension configured) one could set `internal` as file
-        extension internally so that internally `OWNERS.internal` files are used
-        and the existing `OWNERS` files are ignored.\
+        Allows to use a different code owner configuration in a fork. E.g. if
+        the original repository uses `OWNERS` code owner config files (no file
+        extension configured) one could set `fork` as file extension in the fork
+        so that the fork uses `OWNERS.fork` files and the existing `OWNERS`
+        files are ignored.\
         Can be overridden per project by setting
         [codeOwners.fileExtension](#codeOwnersFileExtension) in
         `@PLUGIN@.config`.\
@@ -309,11 +309,11 @@
 <a id="codeOwnersFileExtension">codeOwners.fileExtension</a>
 :       The file extension that should be used for the code owner config files
         in this project.\
-        Allows to use different owner configurations for upstream and internal
-        in the same repository. E.g. if upstream uses `OWNERS` code owner config
-        files (no file extension configured) one could set `internal` as file
-        extension internally so that internally `OWNERS.internal` files are used
-        and the existing `OWNERS` files are ignored.\
+        Allows to use a different code owner configuration in a fork. E.g. if
+        the original repository uses `OWNERS` code owner config files (no file
+        extension configured) one could set `fork` as file extension in the fork
+        so that the fork uses `OWNERS.fork` files and the existing `OWNERS`
+        files are ignored.\
         Overrides the global setting
         [plugin.@PLUGIN@.fileExtension](#pluginCodeOwnersFileExtension) in
         `gerrit.config`.\