Browser.bookmarks.restore default bookmarks
From MozillaZine Knowledge Base
When Mozilla Firefox is started in Safe Mode, a dialog appears with options to reset various user data for the browser — including bookmarks. When that option is picked, this preference is toggled to true, and when the browser starts the default bookmarks are copied over the user’s current bookmarks file.
Possible values and their effects
Do not reset bookmarks to their defaults. (Default)
When starting in Safe Mode, the checkbox labeled “Reset bookmarks to Firefox defaults” sets this preference to true.
First checked in
Has an effect in