Changing Japanese namespace names of MediaWiki
Fragment of a discussion from Support/LiquidThreads
Probably the projects that use the Japanese language setting. Also you should check where the namespace names are used hardcoded in your wiki, for example changing {{#ifeq:{{NAMESPACE}}|ノート|...}} to {{#ifeq:{{NAMESPACE}}|{{ns:Talk}}|...}} or {{#ifeq:{{NAMESPACE}}|{{ns:1}}|...}}, which will make the function work with both namespace names.