The club runs a city-wide challenge in which the goal is to hold the lowest numbered tag you can. I believe there usually end up being 250 or so tags. The initial distribution of tags is based off of one's finish at the previous club championship, with first place receiving tag #1, etc. Thereafter, the next lowest available tag can be purchased for $5.
In any club sanctioned events (leagues, tournaments), and in casual rounds should tag-holders desire, a higher numbered tag (88) would trade tags with a lower number (23) should the higher number beat, not tie, the lower number in that round. This applies only to players on the same card, although off-card challenges are optional. If multiple tag-holders play on the same card, the tags will be pooled and redistributed based on score. It's possible that all three players will change tags, for example, or that only two players will swap.