User is mainly known from a false door found at Khozam (ancient Iushenshen) in 1884.
[1] Here, User bears a long string of important titles, such as Father of the god, beloved of the god, Overseer of Upper Egypt, overseer of the desert lands and overlord of the Coptite nome.
The most unusual title for a nomarch is king's eldest son of his body.
Under the scene is another one that is destroyed, only the caption is preserved naming User with several title, including eldest king's son.
[3] The title king's eldest son of his body caused some discussion in Egyptology, as it is not certain whether he was a real son of a king or whether the title was purely honorific.