A while ago, we conducted a survey of 25 different sponsors and judging agencies, and we sent them questions addressing various subjects. The information presented here is from the results of those surveys. A few of our questions asked about their requirements for addressing envelopes.
How strict are sponsors about capitalization and punctuation on the outer envelope? Will judges disqualify an entry for incorrect capitalization and punctuation?
Almost unanimously, the sponsors replied that if quotation marks were missing or in different places, that would be overlooked, along with other small items, such as commas around the state abbreviation, whether or not the P.O. Box had periods after the PO, abbreviating the state name when it was written out in the rules, and so forth.
Most of the sponsors replied that the envelope just gets your entry to them. It's the information on your actual entry that they are concerned about -- the stuff INSIDE the envelope (or your entry information on a postcard). If you forget a word in the qualifier, your entry will be disqualified. If you don't use block letters when required, your entry will be disqualified. If you give them just your age when your birthdate is required, your entry will be disqualified. If they can't read your writing, your entry will be disqualified.
Some of the sponsors noted exceptions for the envelopes, though. One exception is the infamous "hand addressed" rule. If it is required that you hand address your envelopes and you do not, your entry will be disqualified. Another exception is block letters. If it is required that you write in block letters and you do not, your entry may be disqualified.
To summarize, don't worry about the little things like whether the P.O. Box number has periods on the PO Box, or whether the state is abbreviated or not. Don't get frustrated over quotation marks -- use your best judgment. Concentrate on the main items such as whether hand addressing is required or whether all block letters are required. If you're looking for something to be extremely concerned about, we can always discuss the card vs. paper rule. :-)