Plan for purge all or equivalent one-time emergency situations.

For example, a security vulnerability found requires that you to purge content across the board or across certain huge sets of content. Since there are no restrictions on the number of tags associated with an object, you can have a tag such as ALL_CONTENT or a small number of tags themed ALL_APP1_CONTENT to account for these rare but critical scenarios. Even though these tags can be associated with millions of objects, you’ll only need to purge one tag when these situations arise.