That last post made me think about why I personally #CW for #TransCharacters, as a trans person.

On AO3, #tagging is neutral. A given tag can warn or welcome. On Twitter, including a keyword at the top of a tweet is less neutral, but it can still be searched for.

On #Mastodon, a keyword in the CW line is unsearchable. It makes a statement: this is a warning I think is likely to be useful to a certain % of viewers, whether for #triggers, #squicks, or just general comfort (like with long posts).