According to Wikipedia: In addition, the clause presented a legal problem for those wishing to publish BSD-licensed software which relies upon separate programs using the GNU GPL: the advertising clause is incompatible with the GPL, which does not allow the addition of restrictions beyond those it already imposes; because of this, the GPL's publisher, the Free Software Foundation, recommends developers not use the license, though it states there is no reason not to use software already using it.
My TMAC relies on Groff (mostly the features, but it also works on Heirloom), which is licensed under GPL. Will it wreak havoc if I license the TMAC under 4-clause BSD?
