Writing on the Wall

Thank you for your birthday wishes.
One of the presents i got for my birthday was a book by David Shrigley called 'KILL YOUR PETS'. I really like David Shrigley. This book is full of slogans that kind of make sense but you have to read them a couple of times to get the joke. The book is in a small square format exactly the size of a CD case. This adds to the difficulty in reading the slogans as they are all written in large black capital scrawl. I find this funny also.
When i was a kid there was some graffiti on a wall opposite the shops near where we lived. It said:

IPSWICH FOR UNDERPANTRY AND BEWTY

i always thought that when i grew up, i would understand what that meant. [I also thought that girls grew up they had to wear tan tights]
More recently, i went to an exhibition where you could scribble on wallpapered walls (i copied the line above).
How cool would it be if someone somewhere reading this post knew what that meant???!!!***
Even better: what if you were the person who scrawled that on a wall near my old house.....or any wall, anywhere for that matter!
That would be great if that happened.