Auth string types.
Note that for the Steam2 and Steam3 types, the following ids are also valid values: "STEAM_ID_PENDING" - Authentication is pending. "STEAM_ID_LAN" - Authentication is disabled because of being on a LAN server. "BOT" - The client is a bot.
The game-specific auth string as returned from the engine
The following are only available on games that support Steam authentication.
Steam3 rendered format, ex "[U:1:8307981]"
A SteamID64 (uint64) as a String, ex "76561197968573709"