This directive is only relevant if you need to set up WCCP(v1)
to some very old and end-of-life Cisco routers. In all other
setups it must be left unset or at the default setting.
It defines an internal version in the WCCP(v1) protocol,
with version 4 being the officially documented protocol.
According to some users, Cisco IOS 11.2 and earlier only
support WCCP version 3. If you're using that or an earlier
version of IOS, you may need to change this value to 3, otherwise
do not specify this parameter.