I once got in a lot of trouble with my boss when I was young and worked
for
a U.S. based company. At that time, I didn't understand that there was a
big
difference between British 'tongue-in-cheek' humour, and the much more
direct U.S. type. I was talking on the phone to one of the designers of a
piece of equipment that we sold here in the UK, and asked the guy if he
could arrange to send me some screws for the cabinet, as they were a
thread
that we didn't readily get over here. He asked if I knew exactly what size
they were so I replied, quick as a flash, thinking that I was being funny,
"I guess that they are round about 3/16ths APF." "What's APF ?" the guy
asked. "American **** Fit", said I ...

Stony silence on the phone. Half an hour later, I was summoned to the
boss's
office. Apparently, the guy had been really offended by this, thinking
that
it was a slur on what he considered to be good American engineering, and
had
called my boss to complain about me. Just goes to show how easily offence
can be caused between nations, even when they speak what's basically the
same language ... :-)

It's hard /not/ to interpret such a description as an intentional insult. I
can't imagine what it actually means -- in any innocuous sense, anyway.