What I want here is to make it easier to search for a specific sex in a species where the species is often drawn in both sexes or more. In complex scenes it becomes hard to search for a specie's specific sex. And this makes it easier in general to search for it instead of combining tags that could potentially remove some images that would normally satisfy the user's interest.
For that I would suggest three suffixes:
- *species*_male
- *species*_female
- *species*_ambiguous
The male and female suffixes are for when clear sex identifying features are present.
Ambiguous should summ up the cases where there is no clear indicator or non at all.
The tagging should also be by looks only. If there is for example a male character lore wise, but looks female without any male identifiers, it should be tagged as female as that's what the user is interested in when searching specifically for female. An example for that could be https://e621.net/posts/3990337.
Though I do not know what to do with special cases such as futa, possibly add them to ambiguous as well.