Is there a way to flag a user for the name? I noticed this user's name after answering this question. I don't know about any policies on user names, but this one seems like it could very well violate such a policy.
There's no way to flag an account, but you can flag one of the user's posts for moderator attention and explain in the message. Of course, now that you've brought it to our (mods') attention by posting on meta, there's no need to flag in addition; we'll look into it.
We do allow people somewhat more freedom in usernames than in the content they post, but not as much as is allowed in the "about me" section on their profile. I don't know of any documentation about more specific rules than that.