Confirming his Father's/Rebbe's/Brother's Signature: Ketuvot 28a
To Say that a woman's wedding party was of the type given for a Virgin: Ketuvot 28a
To confirm that a schoolmate used to go to Mikvah [Bath of Purification] and eat Terumah, in order to allow him to eat Rabbinic Terumah: Chagigah 28a, 28b
To say that he personally brought Challah [Dough Tithe] or the gifts given to a Kohen to a certain person: Ketuvot 28b
To Say that a field has a body in it somewhere: Ketuvot 28a
To Show the Border for Shabbat-Travel: Ketuvot 28a
To say that a person's area or a public area was the path of an individual, or an individual's site for Eulogies or Pausing in the Escorting of a Coffin to Burial, and was stolen: Ketuvot 28a
To say that a Family's lineage is [in-]valid: Ketuvot 28b
To say that he was at a couple's Ketzatzah: Ketuvot 28b