# Keeping track of who has viewed which threads? **URL:** \ **Category:** About This Message Board\ **Created:** [September 6, 2012, 11:01pm UTC](https://boards.straightdope.com/t/keeping-track-of-who-has-viewed-which-threads/633921 "2012-09-06T23:01:30Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [September 6, 2012, 11:01pm UTC](https://boards.straightdope.com/t/keeping-track-of-who-has-viewed-which-threads/633921/1 "2012-09-06T23:01:30Z")
How does vBulletin decide which threads it thinks I have or haven’t seen? When I view a forum (the page with the list of threads), the most recent ones (that I presumably haven’t viewed yet?) are shown in boldface. . . BUT . . . I see the newer threads in bold face like this even though I have not signed in, AND even though I routinely delete ALL cookies in my browser. So where is this information saved? Is this maintained by vBulletin in a database on the server, and keyed to my IP number, or some such scheme? (Note, though, I see this behavior only when using Firefox (an older version) on my Winders XP mochine. Most of the time, I use Firefox on my Linux box, where it works different: There, I never see ANY threads listed in bold-face under the same circumstances.) How does this work? ---
**Author:** ![voltaire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voltaire/32/313_2.png) [@voltaire](https://boards.straightdope.com/u/voltaire)\ **Post date:** [September 7, 2012, 2:59am UTC](https://boards.straightdope.com/t/keeping-track-of-who-has-viewed-which-threads/633921/2 "2012-09-07T02:59:04Z")
I think it’s based on IP address and “Last Visited” date. ---
**Author:** ![TubaDiva](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tubadiva/32/507_2.png) [@TubaDiva](https://boards.straightdope.com/u/TubaDiva)\ **Post date:** [September 7, 2012, 2:35pm UTC](https://boards.straightdope.com/t/keeping-track-of-who-has-viewed-which-threads/633921/3 "2012-09-07T14:35:45Z")
I’ve never been able to figure out exactly what the system is tracking, mostly because it doesn’t seem to do a very good job. People have been complaining about this feature as long as we’ve been on vBulletin and we have no idea how to make this come out better, sorry. ---
**Author:** ![suranyi](https://avatars.discourse-cdn.com/v4/letter/s/e36b37/32.png) [@suranyi](https://boards.straightdope.com/u/suranyi)\ **Post date:** [September 7, 2012, 4:57pm UTC](https://boards.straightdope.com/t/keeping-track-of-who-has-viewed-which-threads/633921/4 "2012-09-07T16:57:14Z")
In addition to what’s been mentioned, it must have something to do with your membership, if you have one. Because when I sign in, the list of viewed threads changes. And if I sign in on a different computer, it “syncs”.