What are 'laces' in the cat fancy?

Laces refers to white fur on the back feet. You'll see them on some cat breeds like the Birman and Snowshoe. The Birman is a pointed cat with 'gloves' (white fur on the feet to contrast with the dark pointing). These gloves on the hind feet are referred to as laces. In the Birman the laces finish with an inverted V extended half to three-fourths up the hock. The hock is at the end of the foot and the beginning of the leg; the joint between the tarsal bones and tibia of a digitigrade. The cat is a digitigrade (walks on their toes).

Blue point Birman showing gloves and laces. Image: Wikipedia.

Full image credit: By Claudia Zaino - Albafeles Sacred Birmans, CC BY-SA 2.5 it, https://commons.wikimedia.org/w/index.php?curid=2308036.

The cat fancy likes to use these terms that are applicable to human clothes. Another is 'britches' (or pantaloons) which describes the longer fur at the top of the hind legs of some cat breeds.