In the early 1970s, Taft's common ownership of WTVN-TV and WKRC-TV (channel 12) in Cincinnati was given protection under a "grandfather clause" by the Federal Communications Commission (FCC) from its newly enacted "one-to-a-market" rule. The ordinance prohibited television stations with overlapping signals from sharing common ownership while protecting existing instances. WKRC-TV's signal provided at least secondary coverage to much of the southern portion of the Columbus market. One of WTVN-TV's competitors, Crosley/Avco-owned WLWC (channel 4, now WCMH-TV), was given grandfathered protection through a similar situation with sister stations in Dayton and Cincinnati.