Maybe the problem here is I’m misunderstanding what they are for. I wanted a way for people to add their Twitter and GitHub accounts so that other users could see them. For example, to follow people they meet in the forum.
But it’s becoming clearer that the fields I see in my profile here are really only for authentication, and so are not displayed to others. In fact, in the admin panels, they are treated with the same secrecy as email address, with an explicit button to view.
If I want publicly visible Twitter and GitHub handles, do I have to add them as custom user fields myself?