WordPress MU

When a new user signs up, he enters a username and email address, then clicks Next. Now the username he just picked is automatically inserted in the Blog Domain field. Unless he wants his blog URL to be username.maindomain.com, he'll have to delete the username from that field. Most newbies won't know to do that.

I would like to disable the auto-insertion and also put wording above that field, suggesting how to choose a blog name that will work well as part of a URL.

I found the place in wp-login.php where I could delete the "Just give me a username" part, since I can't imagine anyone will need that. But I can't find where to do the other things I want. Thanks in advance!

You already asked this question:
http://mu.wordpress.org/forums/topic/15592?replies=3

Deanna, you are right. Sorry; I had forgotten, and when I searched the topic I didn't even find my own post! In any event, I didn't get a useful answer yet to the old post. I've clarified my question a bit over there. Thanks.

To do what you have described would require writing a custom signup page.

If your blog owner wants to set their comment setting to user must be registered to comment, giving the potential commenter the option to sign up for just a username makes sense. In our public MU install only about half the users have blogs. The other half signed up to comment on blogs.

wpmuguru, thanks. Yes, that's what I want to do. I just can't figure out where to insert the wording to tell a new user to delete the username from the blog domain field, or better yet, prevent it from being inserted automatically in the first place. I've already inserted text on the first part of the signup page, saying, "By filling in this signup page, I'm agreeing to the Terms of Service" with a link to the TOS.