Create an account for another user

Hi Everyone,

We disabled account creation due to too much spam and bots. I am
trying to manually create an account for a user. I read the docs at
[1] and visited Special:CreateAccount. I then entered the user's
details.

I have not submitted because I'm getting a message:

    Your username will be adjusted to "XXXXXX"
    due to technical restrictions.

I am not sure why I am getting that message. I am trying to create an
account for another user. I am not trying to change my user name.

I have all the wiki privileges and rights. They include bureaucrat and
administrator.

Does anyone know how to proceed?

Thanks,

Jeff

[1] https://www.mediawiki.org/wiki/Manual:Account_creation