From MozillaZine Knowledge Base
Firefox 2.0 introduced Microsummaries for bookmarks — a way to extract a bit of information from a web page and display it in the bookmark’s title. In Firefox 3, microsummaries can be automatically updated to reflect changes to web site designs. This preference determines how often to check for updates to microsummary generators when generator updates are enabled.
Possible values and their effects
A non-negative integer, in seconds, determining the amount of time between microsummary generator update checks. If unspecified, updates occur weekly (7 * 86400 seconds apart).
First checked in
Has an effect in