Wizard mark

When this spell is cast, the wizard is able to inscribe, visibly or invisibly, his personal rune or mark, as well as up to six additional characters of smaller size. A wizard mark spell enables the caster to etch the rune upon stone, metal, or any softer substance without harm to the material upon which the mark is placed. If an invisible mark is made, a detect magic spell or similar magic will cause it to glow and be visible (though not necessarily understandable). The mark cannot be dispelled, but it can be removed by the caster or by an erase spell. If cast on a living being, normal wear gradually causes the mark to fade.

Note: This version of wizard mark originally appeared in the 2nd Edition Player's Handbook for Advanced Dungeons & Dragons from TSR. Its use here is for the purposes of providing context for the campaign only.