What does "?ref=ts" mean in a Facebook application URL?

When Facebook drives traffic to an application, it often append &ref=whatever to the query string. This is useful for figuring out which integration points are working or not. I've figured out what some of these mean. For example:

ref=bookmarks - the user clicked on a bookmark.

ref=game_my_recent - the user clicked on the upper portion of the games dashboard.

What does "ref=ts" mean? It accounts for a ton of traffic. I've viewed source on pages all over common Facebook pages and cannot find a match for ant piece of content generated by any of my applications.

Same question, posted by me on the Facebook developer forum: http://forum.developers开发者_运维百科.facebook.com/viewtopic.php?id=54866

It means 'Top Search' (if you enter a query into the top, and then click on something, it will append ref=ts

As noted, ref=ts is appended to the url whenever a user makes a search in the Top Search input field.

Also note that people tend to copy/paste links in their website and blogs, without trimming useless GET strings. So it is possible if you get a high number of referrers coming from the top search that they are in fact links that propagate outside of Facebook.