As I understand it, the preferred abbreviation for Number is "No."
If we want to then follow that abbreviation with a colon, like in a form for instance, what does style dictate we do?
"No.: 0123456789" (i.e. we preserve the period and add a colon) or;
"No: 0123456789" (i.e. we remove the period and add a colon) or;
"No. 0123456789" (i.e. we preserve the period and do not add a colon)
Is there a strict rule one should follow in this scenario?
Which is preferred stylistically?
Does the convention vary between British and American English?
It's worth mentioning that I'm interested in how this applies to lists of data that use the following format:
First Name: John
Last Name: Doe
ID No.: 0123456789
ID No: 01223465798
ID No. 0123456789