A computer program is a message from a man to a machine. The rigidly marshaled syntax and the scrupulous definitions all exist to make intention clear to the dumb engine. But a written program has another face, that which tells its story to the human user. For even the most private of programs, some such communication is necessary; memory will fail the author-user, and he will require refreshing on the details of his handiwork. How much more vital is the documentation for a public program, whose user is remote from the author in both time and space! For the program product, the other face to the user is fully as important as the face to the machine. Most of us have quietly excoriated the remote and anonymous author of some skimpily documented program. And many of us have therefore tried to instill in new programmers an attitude about documentation that would inspire for a lifetime, overcoming sloth and schedule pressure. By and large we have failed. I think we have used wrong methods.