(See also: Web protocol)

Immersive internet users typically set up a default avatar for themselves when browsing the 'net. If they don't supply one, it ends up being their 'offline-appearance' avatar, which is typically crafted by their client via the neural connector, but occasionally hand-crafted by hackers.

Some servers disallow default avatar use entirely, forcing all its users to appear human. Other servers, especially online multi-player games, often restrict the exact type of default avatar that can be used, or, as a less computationally intense variant, offer their own avatars to choose from while connected to them. Latter is especially popular with small roleplaying games.

Avatar style is parsed on initial connect, only once. Henceforth the data pertaining to it in pre-render computation computation (relevant, for example, for Puppets) is stored internally, often at grossly simplistic levels, such as a simple flag for the avatar gender.

Avatars for Puppets are of course not double-encoded: There is no 'offline-appearance' form. Beyond that, it's a mirror-image of the 'Netizen use' deal, as long as the Puppet is autonomous.

Simulation-bound Puppets are coded into the simulation and their data structures can either be more complex or lacking entirely. It's best not to assume anything about those.

Avatars are bound to certain rules as per the simulation they connect with. A simulation generally has full control over which of the two avatars that are sent with the web protocol or even create new ones for connected Citizens (or autonomous Puppets), but there are established terms for the most common rulesets:

A default-avatared sim simply uses the default supplied avatars.

A human-avatared sim uses the avatars sent as a person's offline-appearance.

There are usually checks in place to confirm that the avatar is indeed human, usually based on a proportion analysis first of the avatar's rig, then the actual surface. If the offline appearance does not match the check, a user is usually expelled. Alternatively, the default avatar is checked (usually more rigorously) - if the default avatar then is human, the default avatar is taken. If neither avatar sent to the server is human, the user is, again, usually expelled at this point - if not, the server simply constructs a human avatar.

Most of the time people will mean Citizen mode if they talk about 'a human-avatared sim'. True OFFL-mode requires human avatars even of autonomous Puppets.

The logic of humanoid avatars roughly checks for a humanoid appearance in default avatars. If given, the avatar is permitted - otherwise, an offline appearance is forced as with a human-avatared sim.

Citizen mode in most settings is indistinguishable from OFFL-mode. It differs in how it treats autonomous Puppets that connect: They get to keep non-human avatars.

Understandably, it's less resource-intense than OFFL-mode, which is why outside of extremely avatar-conscious networks it tends to be used far more often than true OFFL-mode. The distinction is usually not made colloquially, though.

All bets are off here - both avatars sent with the web protocol are ignored in verbatim. The simulation creates new ones, sometimes based on the existing avatars sent, sometimes from scratch depending on what the sim requires.