Allotments 4 All

When I was sending a post this morning I noticed the "Spoiler" button.  I have no idea what it is so thought I would try it out here. 

[spoiler]What is a spoiler?
[/spoiler]

Ok, I remember now.  Duh!

[spoiler]did you work it out?!?![/spoiler]

Yes, Ollie, it came to me as soon as I had posted.  You probably posted a reply just as I was adding my piece about remembering what it was!!