There are places in the AO control system where the term "Apparent" is used as a qualifier to describe the nature of the parameter such as the coordinate system at the actual time.

This is the closest technical word to what should have been "Epoch of Date" in the coordinate system context. According to the Astronomical Almanac, "Apparent" is a generic term that is a technically accepted qualifier, unlike "Current". So in the AO context, the "Apparent" coordinate frame refers to the coordinates at the Epoch of Date and its easy to see how this qualifier would find appropriate application in other radio astronomy contexts as well.