the nfs(5) man page states
The fstype field contains either "nfs" (for version 2 or version 3 NFS
mounts) or "nfs4" (for NFS version 4 mounts). The nfs and nfs4 file
system types share similar mount options, which are described below.
This is incorrect. The fstype nfs can also denote NFS version 4 mounts. fstype nfsv4 is also provided for legacy reasons.
This is fixed in utils/mount/nfs.man of upstream nfs-utils (now reads "The fstype field contains "nfs", for whatever version of the protocol.") There's been a lot of work on that man page which we may want to incorporate.
Bruce, can you pull in and update that man page for us?
Looks like this was fixed as a side-effect of Steved's rebase of
nfs-utils to 1.2.3 for bug 637198. Closing as a duplicate of that bug...
*** This bug has been marked as a duplicate of bug 637198 ***