Manual:$wgExtraNamespaces/ru

Details
configures additional, custom namespaces for a wiki. It can also be used to rename the default namespaces.

This is covered in detail in.

Extensions should not use this setting, instead they should use the hook or load the namespace through.

См. также
It is recommened to define custom namespaces with IDs starting at  to avoid namespace conflicts.
 * Namespace IDs used by extensions – Shows you a list of namespace IDs you should definitely avoid to prevent namespace conflicts, thus the first custom namespace may encounter conflicts even at ID  though   is theoretically possible.