Overview
Besides the prefix of each server, some people can choose a prefix of their own. It works in every server where Petto is, next to the prefixes of the server (a server can have several, and they keep working for everybody). It follows the same rules as the prefixes of a server: a symbol is typed attached (p!help), and when the word after it is not a command Petto stays silent.
Commands
!myprefix alone is the same as show: it says your prefix and whether you can have one. The aliases are !userprefix, !selfprefix and !upfx.

In Discord: !myprefix says whether you can have one, and !myprefix set chooses it.

In Discord: the new prefix works in any server, next to the server's own.

In Discord: !myprefix reset removes it; with none, Petto says so.
Who can have one
You need to be at least one of these:- Boost the Petto support server.
- Have Petto Premium (or a Premium role in the support server).
- Be a Petto partner (the partner role of the support server).
- Be on the Petto team: owner, developers and the site team (staff, testers).
- Have one of the special roles that the team gave the support server.

In Discord: someone who meets none of the requirements gets the list.
What a prefix can be
Up to 5 characters, no spaces, with at least one symbol (., ?, p!, ,): a prefix of only letters or numbers would set Petto off in normal chat. It cannot start with / or be a mention.

In Discord: a prefix of only letters, or one that starts with /, is refused.
For the team
The roles are set with two variables of the bot:PETTO_PARTNER_ROLE_IDS (the partner roles) and PETTO_USER_PREFIX_ROLE_IDS (other roles that give access), both lists of role IDs separated by commas. The support server is the one in PETTO_SUPPORT_GUILD_ID.