Context: Unaspirated or tenuis consonants are occasionally marked with the modifier letter for unaspiration ⟨◌˭⟩, a superscript equal sign: ⟨t˭⟩. Usually, however, unaspirated consonants are left unmarked: ⟨t⟩.

Question: How are unaspirated or tenuis consonants sometimes marked for unaspiration?

Answer: with the modifier letter