<Account name> isn't a valid account name. (Error 3030)

The specified account (user) name is not valid. User names can be from 1 to 20 characters long and can include alphabetic characters, accented characters, numbers, spaces, and symbols, with the following exceptions:

• The characters "  /  \  [  ]  |  < > +  =  ;  ,  :  ?  *
  
  
• Leading spaces
  
  
• Control characters

User names are not case-sensitive.