Searching for commentaries can be a bit of a pain when, peppered throughout the search, there are commentaries that just translate to something like "Untitled" that only exist because the artist elected to leave the title and description blank. I don't think they should have their various commentary tags removed, but there should be a tag that lets users exclude/blacklist them.
My first thought was untitled_commentary, but that's potentially ambiguous with commentaries that just have no title field (Twitter, Tumblr etc.) and would exclude any automated commentaries that don't literally say or translated to "Untitled". As such, I believe placeholder_commentary would be the best tag for this. It's not the most intuitive name, but it gets the point across and lacks ambiguity.