If a user contributes under pseudonym or even anonymously, how does this affect CLAs? Does it help anything if he signs a CLA with that pseudonym?
For books: publishing as anonymous is permitted, but the editor needs to know the author real name, or when needed, the author is required to proof his authorship.
I interpret that a CLA is some kind of agreements to the "editor", so I think you should disclose your real name.
Note: a truly anonymous contributor cannot enforce his own rights (of copyright), so as alternative, you can publish the work in public domain, which usually avoids CLA requirements.