I hope I've got the right part of StackExchange, as this is sort of a weird question.
Lately I noticed that occasionally whenever I opened an NYTimes.com page via a link, the top left hand corner of the web page would always have a string of five alphanumeric characters in small font. While loading the page it would also display this string, except at a larger font.
An example I just encountered:
The link on http://news.ycombinator.com
At first the five character string was "10a98", and after refreshing the NYT page it became "10a8d". I'm using Firefox 13.0.1 on Ubuntu 12.04. Attempts to reproduce another site showing this string failed, but I am very sure that I've seen it quite a few times, and I do believe that this behaviour is not limited to NYTimes.
Edit 1: A screenshot of the same page with the string in the top left hand corner is here: http://imgur.com/a/IMjP5 Taken with and without Firefox's safe mode.
Edit2: I tried the same website, from the same link on HN, on a laptop (with Firefox 14.0.1), and I get the same exact string that I currently have on the desktop (10ab5).
What is the cause of this? Is it possible that it has something to do with the fact that this is the first NYTimes site I browsed during this session?