Hi fido
And, apologies to anyone that I gave away a clue on today's crossword!
They use this lots in online crosswords. Basically, it's an American thing. When they extend their houses, they call it an 'L'. Of course, they can't use just 'L' in the puzzle, to try to spell it out as 'ell'.
Basically, they build rectangular houses to start with, and then bolt on a conservatory type thing on the back, which then makes the building 'L' shaped!
Best Wishes
Chris