TL;DR:
I think we should:
- Add full list of "multiple image" class tags, like sketch_page, to pages solo and duo (and three, four and any like that if they are exist).
- Clarify on solo wiki if background characters and animals in presence of fully visible foreground sentient characters are not reasons to remove solo tag.
- Clarify of characters silhouettes on the foreground are count as proper characters or not. Maybe there is already.
- Add some sort of tag for "creatures" that are not count for removing solo but that are still counts for duo. background_character maybe? IDK.
I just tried to search solo duo and found surprisingly lot. Checked wiki for solo. Then looked for solo duo -multiple_images and still found surprisingly lot.
I added multiple_images to a post, somehow decided to look for image history and found that it was removed at one point and replaced with sketch_page. Changed back. Looked for the tag on wiki again. Found it hidden behind "etc".
So, I suggest to add all those multiple_images-like tags to the wiki page. And to "duo", btw.
Then, I changed "solo" to "solo focus" here:
Two characters (as in, same level of intellect and human-like), so everything is fine here (I hope. After writing all this, I'm not sure anymore).
Then there was this image:
A girl and a fox. So kinda not solo. Looked carefully on both wiki pages. Duo has this:
Any creature physically present within the scene, in whole or in part (including things like disembodied_hands).
Compare with solo
Someone physically present within the scene, in whole or in part (including things like disembodied hands).
This somewhat implied that for duo, absolutely every animal or animal-like bot is count as character and for solo they only count if there is no fully drawn (that is, no disembodied_something) sentient beings on the foreground plane (That is, lots of animals and some human shape on background means it's not solo and all the animals are characters. One human on the front with same animals anywhere is solo).
Also, in duo.
Any characters or creatures in the background, regardless of distance and size difference.
That could imply that for solo tags, if there's one characters on the foreground with unrecognizable human shapes on the background, it's solo. If there is one silhouette, like with mermaid above, that's also solo. Or not, I don't know. What I think is that it should be clarified on "solo" wiki.
Before anyone suggest to use my common sense, it tells me to ask here 'cause it's not really common (my friends in full seriousness tell me to "try think like everyone" at one point of time). Also, it tells me that sketch_page and multiple_images are not mutually exclusive, yet it is for someone who changed tags before me.
Anyway, if there can be solo duo with "someone and a creature", some sort of tag for this "non-character" creature should be there. Can't think how it should be named, but I really think it should be, that way it would be easier to find tagging errors.
P.S. And it would be really great to have some sort of warning system for tags. Like, "you tagged tag1 and tag2 without any of this tags: <tag list>". Dreams, dreams...