categorizer/hashtag
Differs from sau'e'u in that this word denotes the general body of subjects to which the discourse is related by focus. sau'e'u denotes the specific manifestation/substantiation of those topics in a given, indicated form. They are closely related, however; arguably, the real difference is the way in which the tagged subject relates to the utterance: does it point out the primary point of the message so that people know about what it is (sau'e'u), or does it indicate a general idea or event which has many possible conversations under its umbrella (this word; those specific conversations can be indicated by topicalization)? This is only one meaning of hashtags; other free modifiers can be used for other meanings.