Are there any alternative formulations of the five skandas?

Considering the 5 skandas of 1. Form 2. Feeling 3. Perception 4. Volition 5. Consciousness I was told during a study group once that this was only one of many possible formulations of the skandas and other groupings and numbers of skandas were possible and used. However I have never come across any variation in this scheme. Is anyone aware of any alternative formulations of the five skandas?