[klez]

Reading the comments here I'm under the impression that people think OP wrote the manual for `su`, but the interesting fact here is he wrote the GNU coreutils implementation of `su` itself.

Debian (stable, at least) doesn't use his version anymore. The HISTORY section of the current manual says

> This su command was derived from coreutils' su, which was based on an implementation by David MacKenzie. The util-linux version has been refactored by Karel Zak.