I wasn't sure where to post this as there is no specific forum for the tag editor in Properties or the right click menu Edit ID Tags.

Is there a way to permanently add custom tags to the list when choosing ADD in the Edit ID Tags or Properties ID tag? If I click ADD and add a custom tag, the custom tag is available as long as that session is open, like when editing multiple files at once. If I move to another file and click Add, the custom tag I created is in the list. However, once I save or exit the editor / properties, the custom tag is gone.