Test:Showhide

From EcoReality

The "showhide" extension allows you to have an area of the window that is hidden or shown by clicking on a link, similar to the "Contents [hide]" that is on pages with tables of contents.

Here is the part that is always shown.

Then there is a "hider", which is the link that toggles the display of the hidden part: -->

I haven't thought of good reasons to use this so far, but it might be useful for sidebars of wordy explanation text or something similar.

That said, it's installed -- use at will!