Just a note, but there's no need to specify that something's solo KA in the source. If anything that just makes searching by source more annoying.

The BD tag is useful. The S2 tag is sometimes necessary. Putting those things into new meta tags isn't going to happen, judging by the response I got on IRC when I proposed an "uncredited" tag.

I personally think "solo KA" in the source useful

I also find all of those extra details in the source pretty helpful, to be honest. It's the quickest and easiest way to learn that something is "solo KA", especially.
I didn't know it was possible to search by source either, to be fair. And am still not sure exactly how that works.

Disgaeamad said:
Just a note, but there's no need to specify that something's solo KA in the source. If anything that just makes searching by source more annoying.

Just some heads up, but if after the number of an episode or the OP/ED you leave a space, it won't mess your search whatever you write after. If you write in the search bar "source:ED" it will show you all the EDs, regardless if they are solo animated or not.

See the example: https://sakugabooru.com/post?tags=pripri_chii-chan+source%3Aed

So I don't see the harm of keeping track of solo episodes/openings/endings. We are constantly asking users of not changing tags without a source, and noting solo things it is by itself a sourcing method. Forget to write it and someone not used to the show in particular has to make the effort of going to check the credits to try to confirm the veracity of the post.

The information is useful, but the current state of the source field is a nightmare. We're definitely getting rid of it and instead integrating the episode/movie's key staff into the site itself whenever we get around to the booru renewal. It's going to be a massive pain but the result will be worth it.