Many staff are contracted as a fixed term hire on a repeating basis. (i.e. hired for a fixed period of time e.g. 3 months each year)
The ability of a Domino Administrator to be able to change the status of a person from Active to inactive inactive to active would remove the need to delete the person and then re-register them the next time they are hired again.
When a person document is inactive it should not appear in Notes user email lookups, directory lookups or email delivery.