The file `hyphen.us' is identical to the file `hyphen.tex', part of the TeX system written by Donald E. Knuth; the master file can be found at ftp://labrea.stanford.edu/pub/tex/dist/lib/hyphen.tex . It has been renamed for consistency, i.e., to make patterns available under the filenames `hyphen.<language>', e.g. `hyphen.de' or `hyphen.uk'. See the file itself for a copyright notice.