Currently, the Incest tag is used based on outside information, and it's very rare that an image actually includes internal evidence that the characters are related. As somebody who doesn't follow every single cartoon or read every single comic, I wouldn't know these characters are related, so I can look at images of similar looking characters and enjoy it, but if I see the "incest" tag it just ruins it for me. I feel like we should be true to our rules and keep to only what we see.

There's also the technical_incest tag, which would be even iffier to tag under TWYS, but I'd be fine with that. I could actually blacklist the incest tag right that way and use excludes to allow known "technicals" to get through.