Meaning of 'secret key stub' (gnupg-1.4.1)

Jaime Suárez <[email protected]> Thu, 17 Mar 2005 18:10:29 +0100
Newsgroups gmane.comp.encryption.gpg.internationalization
Message-ID <[email protected]>
g10/keygen.c:2913
"writing secret key stub to... "

What is a "secret key stub"? I don't know how to translate it.
Thanks.