- Description: Sex between family relatives, even those not related by blood.
- Notes: Is required for the aunt, brother, cousin, daughter, father, granddaughter, grandfather, grandmother, inseki, mother, niece, sister, and uncle tags. For non-parody works the proof must be contained within the gallery's contents. For parody works use the mainline canon (see the discussion page).
- Gender: The genders of the participants determines whether the tag is placed in misc, male, or the female namespace. If the participants are of the same sex use that namespace, any combinations of the two different genders use misc:incest.
- Japanese: 近親相姦
- Slave Tags: Female, Male, Misc