When I was a student I used to spend holidays working for a flower company that supplied the M&S flowers.....
I wrote the gift cards and the customers were limited to a set number of letters.
When writing the cards abbreviations were NOT allowed. Ever. Not even when they came in from the customer. Reputation to protect etc blah blah.
It was a nightmare. The cards were standard size flower cards, and Christmas takes up a lot more space than Xmas. We also had to write "and" if "&" was used..... To make matters worse groups of family members would send one greeting.
Imagine -
To Betty & Steve, Merry Xmas & a Happy New Year, from Arthur & Penny, Jim & Bev, Charlie & Pete xxx.
This would become:
To Betty and Steve, Merry Christmas and a Happy New Year, from Arthur and Penny, Jim and Bev, Charlie and Pete xxx.
Ok, so not a huge difference, but massive on a teeny little card!
The store assistants also used to abbreviate EVERYTHING to fit very long messages into the letter allowance, to the point where you could end up with 50% more. And most of them couldn't spell Margaret - Margret featured a lot and we had to correct that too.
And at Valentines we were not allowed to write anything even vaguely saucy, and if an "unacceptable" message was accepted in store we had to call the customer, tell them we couldn't send that message and ask for a more "appropriate" one hehehe.