I can't get away w/ too much of that, not anonymously, anyway. Last job I put an old control knob on the trash compactor panel and marked "more pressure" or something like that. One of the coworkers walked up later w/ trash and saw the modification and guessed immediately who did that.
I worked as a stock clerk at VDOT for a few years. I used to come up w/ other terms for the acronym V.D.O.T.- like "Very Dense Ordered Tools" on a crate of tools- they though it was funny on the other end, too.
i love a good joke , this morning we were driving by the library which just got a new metal roof. i looked up and saw a man walking across the peak of the roof with a caulking gun in his hand. i grabbed up the phone and made like i was calling 911. my wife asked what i was doing i said " calling to report that there's a man on the roof of the library with a gun" she just didnt see the humor in it though.