This tip is probably old news for some but if not, is really handy to know. It pertains to the right click commands that appear when clicking off a tab (for instance: "open all in a floating window" or "close all tabs"). It is useful to know that this applies only to the windows that are tabbed together and NOT to all opened windows in L4.

In the picture above, I clicked on multiple links in the guide on the left, resulting in opening all the resources on the right (with the red frame). Right clicking on these tabs and choosing close all tabs only close those on the right and leaves the guide and note file on the left open. This applies to floating windows also.
Again, I know this will be old news to the L4 gurus out there but if a daily user like me can have discovered it only today, I suppose there must be others who would benefit in knowing. This is really useful whenever one is looking up a series of hits from a window from one side (search results, guides, etc) and saves time to close all the result windows in a hurry.