[ryandrake]

But OP was not planning on returning the letter, so it would never be scanned.

I think the BBC could have solved this preemptively, by simply making the letter say "Please do not write below this line, if you are returning the letter."

[elcomet]

Why would they waste ink to print this ? If he doesn't return the letter, then it doesn't matter...

[DonsDiscountGas]

Or it's a template that they use for a lot of things, many of which are intended to be returned, and nobody took the step to remove it since there is no harm in leaving it.

Also:

> Replies to letters are of course common whether they're expressly requested or not.