We prefix all our custom headers with `X-Ark-` (for auth tokens, request IDs for logging and such), so in this case it's `X-Ark-Compliment`.

Also, another thing we do to propagate joy in engineering culture is make heavy use of Phabricator macros in the code review process. It adds a lot of humor to the situation to have somebody draw attention to a bug in your code by pointing it out with an epic skateboard accident: http://giphy.com/gifs/fail-SMwheKIMDwA00