- Article ID is used to assign an article to a tag. The article is displayed before the results list, much like the category description is displayed before the articles in category/blog view.
- Priority field is not actually used. It was introduced years ago to support "weighted" tags (as in "some tags are more important than others"), for a module that was never released to public. The field remains there to grant backward compatibility. Also, it could serve as an "hook" for future development.
- Default:
-- sets checkbox fields options checked by default
-- pre-select an option of a select field
