That field sets the $LANGUAGE variable. For legacy reason, some translation catalog files are still located in /usr/share/locale/zh_CN.GB2312/LC_MESSAGES (like gqview), that's why zh_CN.GB2312 has to be present. Most apps have migrated to zh_CN/LC_MESSAGES, but a few apps still haven't.
That field sets the $LANGUAGE variable. For legacy reason, some translation catalog files are still located in /usr/share/ locale/ zh_CN.GB2312/ LC_MESSAGES (like gqview), that's why zh_CN.GB2312 has to be present. Most apps have migrated to zh_CN/LC_MESSAGES, but a few apps still haven't.