There are different opinions about this but primarily it depends on the cells that you are growing. In differentiated cell lines the cells wont get reclocked at all.
In the lab I work in, we dont consider that the cells can be reclocked.
The best way of labelling would be labeling the cell lines as P x + y (where x is the passage number of the cells when they have been frozen and y is the current passage number), for e.g. P 2 + 6.