Q: Why do some users complete forms all in capital letters?
This is because early teleprinters and computer systems had no provision for lower case. Mixed case teleprinters came on the market in the 1930’s, but the standard US military teleprinter of World War II was the Teletype Model 15 (produced from 1928 to 1963) which only printed in upper case. This exposed an entire generation to official communications and reports typed in all upper case. This ‘official’ style was then duplicated by users of typewriters by engaging the Caps Lock toggle key.