Since I’ve been thinking I ought to write about my work more often, and inspired by the strangeness of this incident, here goes.
I’d been trying to debug how a few ?s came to be in an ad banner tag submission. I’d dug into change logs and other points where we log transactions to no avail. Since we’d never seen anything like it before, I’d basically decided I’d spent enough time on it and was about to resort to a “it was caused by network ghosts” type explanation. I figured the ?s came from some erroneous network transmission.
On our system, there was nothing strange in the tag field whatsoever. On the adserver though, there appeared some question marks, looking like this:
Then, though when I don’t really know, it hit me. I should view that offending code in a more verbose setting, don x-ray specs if you will – my first choice was VI. Lo & behold, the offending characters appeared before my eyes.