My son's NET teacher uses "period" instead of "fullstop" in dictation.
My son knows "period" equals to "fullstop", but he does know the exact word and pronounciation of "period", he only knows it starts with the letter "p".
Growing up in the UK i never knew they use "period" in US, so when i was working for a US company and my Colleague and i was putting something together she was talking then "period" i was sooooo puzzled and she said"just up a "period" there so i typed "p" and she said "WHAT are you doing???" then she explained to me that in US they say "period" instead of "fullstop". I was soooooooo we both saw the funny side and laughed it off, when she returned to the US she told everyone in the dept and i was FAMOUS for the wrong reason!! hehehe.....
anyway, a little off topic but just want to share with you my story!