I hadn't actually thought about it first pass through... but:

Here, ``person.rank`` is this person's rank "all time".  It is a value cached in the db that gets recalculated everytime someone near them on the leaderboard is awarded a badge.

``rank`` is this person's rank for "this time frame".  It is calculated by this process:  https://github.com/fedora-infra/tahrir-api/blob/develop/tahrir_api/dbapi.py#L661