[root@ibm-x3550m3-03 ~]# lsb_release -sir
RedHatEnterpriseWorkstation 6.5
[root@ibm-x3550m3-03 ~]# rpm -q nfs-utils
nfs-utils-1.2.3-38.el6.x86_64
[root@ibm-x3550m3-03 ~]# exportfs 
/tmp            <world>
[root@ibm-x3550m3-03 ~]# mount.nfs -overs=3  localhost:/tmp  /media/
usage: mount.nfs remotetarget dir [-rvVwfnsih] [-o nfsoptions]
options:
        -r              Mount file system readonly
        -v              Verbose
        -V              Print version
        -w              Mount file system read-write
        -f              Fake mount, do not actually mount
        -n              Do not update /etc/mtab
        -s              Tolerate sloppy mount options rather than fail
        -h              Print this help
        nfsoptions      Refer to mount.nfs(8) or nfs(5)

[root@ibm-x3550m3-03 ~]# echo $?
0
[root@ibm-x3550m3-03 ~]# mount.nfs -o vers=3  localhost:/tmp  /media/
usage: mount.nfs remotetarget dir [-rvVwfnsih] [-o nfsoptions]
options:
        -r              Mount file system readonly
        -v              Verbose
        -V              Print version
        -w              Mount file system read-write
        -f              Fake mount, do not actually mount
        -n              Do not update /etc/mtab
        -s              Tolerate sloppy mount options rather than fail
        -h              Print this help
        nfsoptions      Refer to mount.nfs(8) or nfs(5)

[root@ibm-x3550m3-03 ~]# echo $?
0
[root@ibm-x3550m3-03 ~]# cat /etc/issue
Red Hat Enterprise Linux Workstation release 6.5 Beta (Santiago)
Kernel \r on an \m

This request was not resolved in time for the current release.
Red Hat invites you to ask your support representative to
propose this request, if still desired, for consideration in
the next release of Red Hat Enterprise Linux.

This is more important than the help text bugs, since this actually might affects someone's scripts. Again, needs to be checked and done upstream first though.

With the similar steps, seems `mount -o<Option List>` without a space could work as normal options, according to the man pages, this syntax should be a kind of mistake.

== On RHEL-6.8 ==
[root@kvm-guest-05 ~]# mount -overs=3 localhost:/ /mnt/nfsmp/
[root@kvm-guest-05 ~]# echo $?
0
[root@kvm-guest-05 ~]# uname -r
2.6.32-642.el6.x86_64
[root@kvm-guest-05 ~]# rpm -qa|grep nfs-utils
nfs-utils-lib-1.1.5-11.el6.x86_64
nfs-utils-1.2.3-70.el6.x86_64
[root@kvm-guest-05 ~]# mount |grep mnt/nfsmp/
localhost:/ on /mnt/nfsmp type nfs (rw,vers=3,addr=::1)


== On FC 24 ==
[root@dhcp-12-154 ~]# mount -onoac localhost:/nfs /nfs_in/
[root@dhcp-12-154 ~]# echo $?
0
[root@dhcp-12-154 ~]# mount | grep nfs_in
localhost:/nfs on /nfs_in type nfs4 (rw,relatime,sync,seclabel,vers=4.2,rsize=524288,wsize=524288,namlen=255,acregmin=0,acregmax=0,acdirmin=0,acdirmax=0,hard,noac,proto=tcp6,port=0,timeo=600,retrans=2,sec=sys,clientaddr=::1,local_lock=none,addr=::1)
[root@dhcp-12-154 ~]# uname -r
4.8.6-201.fc24.x86_64


== In man pages ==
-o, --options opts
Use the specified mount options. The opts argument is a separated list.

Red Hat Enterprise Linux 6 is in the Production 3 Phase. During the Production 3 Phase, Critical impact Security Advisories (RHSAs) and selected Urgent Priority Bug Fix Advisories (RHBAs) may be released as they become available.

The official life cycle policy can be reviewed here:

http://redhat.com/rhel/lifecycle

This issue does not meet the inclusion criteria for the Production 3 Phase and will be marked as CLOSED/WONTFIX. If this remains a critical requirement, please contact Red Hat Customer Support to request a re-evaluation of the issue, citing a clear business justification. Note that a strong business justification will be required for re-evaluation. Red Hat Customer Support can be contacted via the Red Hat Customer Portal at the following URL:

https://access.redhat.com/