Sort of like the walking fingers logo of the yellow pages is copyrighted, so all generic yellow pages have lines through the fingers to avoid the copyright problem.
Logos are
trademarked, not copyrighted -- there is a difference.
However, the "walking fingers" in and of themselves are
not trademarked -- they were originally created by AT&T in the early 1960s, but it allowed their free use in order to promote the Yellow Pages concept (e.g., allowing businesses to use the logo as part of urging customers to "look us up in the Yellow Pages").
The various Yellow Pages publishers, though (both "generic" and those currently published by what we used to call "the phone company"), all have their own version of the "walking fingers" logo, and those versions are trademarked by the various publishers.
Incidentally, I note that my 2012 AT&T San Fernando Valley East Yellow Pages do
not have the "walking fingers" on the cover; it does have the trademarked slogan "The Real Yellow Pages" that AT&T inherited from BellSouth, as well as a plug for YP.com.