 People don't need to see that the username ends on :matrix.mit.edu, since it could be confusing. Instead, ask for just kerb (and show @mit.edu perhaps), and keep the bottom message explaining that their Matrix username is @[kerb]:matrix.mit.edu (or whatever is best for user experience)
People don't need to see that the username ends on :matrix.mit.edu, since it could be confusing.
Instead, ask for just kerb (and show @mit.edu perhaps), and keep the bottom message explaining that their Matrix username is @[kerb]:matrix.mit.edu
(or whatever is best for user experience)