Licensing/Bibtex

Original License Text
% Copyright (C) 1985, all rights reserved. % Copying of this file is authorized only if either % (1) you make absolutely no changes to your copy, including name, or       % (2) if you do make changes, you name it something other than % btxbst.doc, plain.bst, unsrt.bst, alpha.bst, and abbrv.bst. % This restriction helps ensure that all standard styles are identical. % The file btxbst.doc has the documentation for this style.

Variants
There are several variants of the Bibtex license which, while worded differently, evaluate to the same meaning.

%%%    license         = "Unlimited copying and redistribution of this %%%                        file are permitted as long as this file is %%%                        not modified. Modifications are permitted, %%%                        but only if the resulting file is not named %%%                        path.sty regardless of case",

%% This file may be modified for individual use. %% %% A modified version of this file may not be %% distributed under its original name.