the 10round rule is just 1 restriction of many no handgun may be manufactured within California, imported into California for sale, lent, given, kept for sale, or offered/exposed for sale unless that handgun model has passed firing, safety, and drop tests and is certified for sale in California by the Department of Justice. Private party transfers, curio/relic handguns, certain single-action revolvers, and pawn/consignment returns are exempt from this requirement.
Additional information on the Roster of Certified Handguns can be found at California Code of Regulations, title 11, section 4070. oag.ca.gov/firearms/certified-handguns/search

A compliant handgun just means it is legal to purchase this gun in your state. Gun laws vary from state to state, and CA has gun laws that are very strict, "compliant" is just to help you know what guns you can buy as a CA resident

Juan, for any handgun to be CA leagl, it must be on the CA DOJ handgun roster. Even if a gun is otherwise compliant, if it's not on the roster, it's not legal.

Juan, this is just one current restriction. Handguns legal in CA must also appear on the CA DOJ approved Roster (unless a Single Action Revolver ​ that have at least a 5 round capacity with a barrel length of at least 3inches and an overall length of at least 7½ inches are permitted as well as Single-shot pistols​ that are top-break or bolt-action with a barrel length of at least 6 inches andhave an overall length of at least 10½ inches are permitted.) here : https://oag.ca.gov/firearms/certified-handguns/search?make=All