Comments

@Ian: If you need a comment to explain trickery, remove the trickery.

Depends on the level of "trickery", and the audience. I have been known to insert comments explaining, e.g. hashes that use "well known" properties of twos-complement arithmetic, at the request of a supervisor who offered the alternative of a 4x slower approach. These days, there is no real lower limit to the skill and knowledge of potential code readers.