On Fri, 04 May 2012 19:24:07 +0100, John Rumm
wrote:

Well, T would be one plank meets the middle of another at 90 degrees - a
T shape.

L would be a square corner...

As for E, both of the above perhaps!

Sorry, I was expecting them to stand for something (egg, lettuce,
tomato) rather than something so simple!