• phabricator-form-view
  • Added in https://we.phorge.it/rP93938765c371c2d4cceff7f725d2243ecfa3cba2, usage removed in https://we.phorge.it/rPfe2a96e37ff03b003cb10928e6d9f077dd44aa05
• phui-header-tags
  • Added in https://we.phorge.it/rPe8bb24fd60724492ac3b28fdee759e4b079342c9, usage removed in https://we.phorge.it/rP9baa965b8609dc6412c137e0e1502542a9fcea31 by using phui-header-action-*
• policy-space-container
  • Added in https://we.phorge.it/rP4811e6e7c1226d3c51649f47c2e7b49beb68aa19, seems to have never been used

Grep the code for each CSS selector (grep --exclude="*.css" -R 'some-search-string' .), also do partial searches, get no results.