I am confused by the variation in terminology related to the 16th Ga Cavalry Battalion or Regiment and its relationship to the 13th or not.

Comments on the record cards indicate that the 16th Battalion was enlarged to 10 companies and renamed the 13th Regiment, effective May 2 1864.

Service records for Wm B Daniel show him in both the 16th Battalion and the 16th Regiment with a cover card of the 13th Ga Cav.

Service record for WJ Haynie have a cover of 13th Cav, and show him in the 1st Partisan Rangers, then the 16th Battalion.

Was there a separate unit called the 16th Regiment?
Or are they the same thing?