news to me: yum doesn't recognize --force option

[Tom Poe]

# yum install libdv-1.0.0.0-1.fc6 --force
usage: yum [options] < grouplist, localinstall, groupinfo, localupdate, 
resolvedep, erase, deplist, groupremove, makecache, upgrade, provides, 
shell, install, whatprovides, groupinstall, update, groupupdate, info, 
search, check-update, list, remove, clean, grouperase >

Command line error: no such option: --force

What is this?  Any help appreciated.
Happy Holidays, Tom