set_username_for: TxDescriptor<
    {
        signature?: MultiSignature;
        use_allocation: boolean;
        username: Binary;
        who: MultiAddress;
    },
>

Set the username for who. Must be called by a username authority.

If use_allocation is set, the authority must have a username allocation available to spend. Otherwise, the authority will need to put up a deposit for registering the username.

Users can either pre-sign their usernames or accept them later.

Usernames must:

  • Only contain lowercase ASCII characters or digits.
  • When combined with the suffix of the issuing authority be less than the MaxUsernameLength.