Hello and thank you for your question.
With a few exceptions, below, all you need to do is type or print
entries, if possible, using black ink.
The exceptions are certain forms, usually where there are individual
boxes for each letter that need to be machine-read, and the place
where you would need to write in capital letters a substitute for the
mailing label that the IRS provides.
Use the IRS label. Otherwise, please print in ALL CAPITAL LETTERS
Marking Instructions for Tax Form 8655:? Use black or blue ink only. ?
Please print legibly. Use one character per block. ? Use only capital
Please use ALL CAPITAL LETTERS in the spaces provided
Topic 752 - Form W?2 ? Where, When, and How to File
It is your responsibility, as an employer, to file Copy A of Form W-2 (PDF),
Type all entries using black ink and, if possible, a 12?point Courier font.
It's the same in Missouri. If a form needs to be scanned for coding,
there are certain lines where all caps are needed. Otherwise it's not
Arkansas wants blue or black ink, but they don't specify capital letters.
In searching for 'capital letters' issues, I came across some tax
protestor nonsense, for example
There is no magic surrounding legal names, capital letters, etc., and
you should ignore these sorts of sites.
Search terms used:
"capital letters" instructions site:irs.gov
"capital letters" instructions missouri tax
Thanks again for letting us help