Orthogonal to the choice of video signal format is the choice of audio format. Audio can be recorded as Normal , or HiFi , or both. Normal audio has a single track, while HiFi audio is stereo. Normal and HiFi tracks are not mutually exclusive, as they are recorded on different parts of the tape. Most home VCRs can play back the Normal track only.
Every manufacturer has their own labelling scheme to indicate the quality of their tapes.
Here is a chart for the tapes we use in the lab.