VRChat have a official documentation about the trust system, click here to see it.
VRChat's ranks can be earned through contributing to the platform through creating avatars and/or worlds. You can also earn trust by collecting friends and spending time in VRChat. All of these factors play a huge part in your amount of trust.
Ranks are earned in the following order:
New User >> >> User >> Known user >> Trusted user >> Friend
The "Friend" rank is automatically given to anyone who you add to your friend list. This is not a rank earned through trust.
Additionally, there exists a special rank called “Nuisance”. These users have caused problems for others, and will have an indicator above their nameplate when your quick menu is open. Most of the time, these users' avatars will be completely blocked, and their mic will be automatically muted.
Please note that you must have an official VRChat account in order to be able to earn trust and climb the ranks. If you are using an Oculus, and use your Oculus account, your rank will stay as a "Visitor".
The safety system serves as a means to safeguard against malicious users or to optimize your in-game experience. Currently, we offer four safety settings: "none," "normal," "maximum," and "custom."
"None" activates all safety features irrespective of the user's rank. "Normal" restricts what is displayed for lower-ranked players. "Maximum" limits the displayed information for medium and lower-ranked players. "Custom" allows you to personalize which ranks can display specific information.
When you reach the "Known user" rank or above, you can choose to "appear as a user." This option will display your user rank above your nameplate and will be recognized as a user by other people, in accordance with their safety settings.