If they use a "frequency shifting box" which nobody hears for the FM translator, then the AM parents's 3 or 4 call letters and city of license is all that's required. Even the FCC realizes that station ID's are an unnecessary burden.* Sooner or later except for "branding" there will be no required station ID.99.3 is a translator and cannot therefore have a traditional full station callsign.
*Back before WW2 aircraft could "vector" using AM stations. Especially at night. Analog tuning tube radios were not all that stable. The station ID insured you were vectoring off of 650 WSM Nashville instead of 660 New York.