Is it permissible to write on a grave or place a marker to identify it?

Question:
He says: Honorable Shaykh, may Allah grant you success, is it permissible to write on a grave to identify it or to place a marker?

Answer:
Writing on a grave is forbidden; it is not permissible. No number, no letter, and nothing else. Writing on graves is not permissible, nor is plastering them, nor hanging lamps on them, nor raising them more than a hand's breadth. All of these matters are forbidden because they lead to exaggeration and to shirk (associating partners with Allah). Yes.