Comment 3 for bug 1689494

Hello again,

"Keep recently closed" keeps closed tabs (an also configurable number of) tabs around when they are closed instead of actually closing them and hence release associated resources. This means that they basically become invisible but continue to consume memory and are destroyed only when so many further tabs are closed, that they are evicted from the recently closed list. This implies that e.g. if you perform some unsaved modifications like adding annotations, close the tab and then restore it, these modifications are not lost.

Best regards, Adam.