From MozillaZine Knowledge Base
SeaMonkey allows users to restore previously-closed browser tabs. This preference controls how many tabs you can restore.
Possible values and their effects
A non-negative integer indicating the number of tab histories to save for later restoration. Default is 3.
- When this preference is greater than 0, memory will not be immediately freed when closing a tab.
- This is a SeaMonkey-only preference. For equivalent Firefox behavior, see browser.sessionstore.max_tabs_undo (and browser.sessionstore.max_windows_undo).
First checked in
Has an effect in
- SeaMonkey (nightly builds after 2006-09-29) and prior to SeaMonkey version 2.1
- Bug 152391 - Closing a Tab should add Undo option when applicable
- Bug 350416 - Closing a Tab should add Undo option when applicable