implied futanari
When a character in the image seems to be a futanari, but it's not 100% certain.
Signs of futanari include intercourse with a stomach bulge and cum, condom wrappers or penetrative sex positions with thrusting and sex noises.
Whether the character is canonically a futanari or not, whether related pictures have a penis showing or not, and whether the artist clarifies that it is futanari or not aren't relevant. So long as it cannot be confirmed visually, this tag can be used.
This tag can overlap with futanari for the sake of usability and blacklisting, due to tags like futa with female/futa with male.
For a comprehensive guide on how to use this tag, see Danbooru forum #272717.