Folder tabs can be locked in a number of different ways. Primarily, when a tab is locked, it always displays the same folder. It can also be prevented from closing, although this is optional.
To lock a tab, right-click on it and choose a command from the context menu's Lock Tab menu. You can also hold Alt and click a tab to cycle through its lock modes.
The different ways a tab can be locked are:
Locked tabs may be protected against accidental closure via a setting in Folder Tab / Locking.
This will block most methods of closing individual locked tabs, and also hides their close buttons. This does not generally affect things which close multiple tabs, such as closing the entire window, closing the dual file display, or loading a new tab group, unless otherwise noted.
You can also use the lock commands to lock or unlock multiple tabs at once; select the commands from the menu while holding down the following keys: