The Keyword/Option Summary in the 6.2.5 manpage does not
include sslfingerprint, which complicates finding out
whether it is considered a server or a user keyword.
Based on experimentation, it seems to be user, which I did
not expect. Intuitively, the server's key (and hence the
key's fingerprint) seems like a property of the server rather
than of a user.
Other keywords missing from the summary, but described earlier
in the manpage, are idfile, lmtp, set invisible, set showdots,
sslcertck, and sslcertpath.