Attribute values (tags) for items. Note that this is different from ItemRequest.ItemAttributes -
the values set here are "tags" for an item, such as color or clothes size. Tags are searchable by users and
may be added or removed from the system at any time.
- Terms, The TermValues (string/text based attribute values).
- Numbers, The NumberValues (numeric attribute values). These are currently
not in use and may be removed in the future.