A peg family is the set of tokens that track the same reference - the ten USD tokens, the four EUR tokens, the gold pair. Grouping by peg rather than by issuer answers the operational question: which family does my invoice belong to?
Families matter for reach too: a corridor that clears in Singapore dollars is served by the SGD family regardless of which issuer's token carries it, and a family's size is a rough proxy for its liquidity and tooling depth.
Thirteen peg families trade on U.CASH, ranked by size on the stablecoins ranking, each family linking to its currency page and each token to its own asset page.
Every term behind the rails, the assets, and the settlement.