The documentation said the following : 
"A comma-separated list of destination domain names, domains, IP addresses or other network CIDRs to exclude proxying."

4.8 4.10 most probably other recent openshift version which use same version of curl

Using CIDR in no_proxy won't have effect on "curl" command launch inside the pod, because curl does not handle CIDR in no_proxy.
So the documentation need to state that CIDR in no_proxy won't be handled by some tool like "curl" and for those one it is recommanded to work with them with FQDN and wildcard.

See the following BZ for more detail : 
https://bugzilla.redhat.com/show_bug.cgi?id=1873478