Should Co have a period?
Moreover, should Ave have a period?
Occasional Moderator. In BE, abbreviations generally donot require punctuation. The middle path is, as has beensuggested, to include a full stop (period) if theabbreviation does not include first and last letters - So St andAve have no punctuation just because they areabbreviations.
Similarly, do you use periods when abbreviating states? Traditional abbreviations for states andprovinces begin with a capital letter and end with a period.The two-letter postal service abbreviations are all capitals withno periods. They are not set apart by commas. They areused only with addresses on letters, envelopes, and packagesto be mailed.
Also asked, do you put periods in acronyms?
There is no strict rule on using periods (fullstops) in acronyms. You don't see N.A.S.A, B.B.C, orN.A.T.O often because they are so popular/familiar. However,you might have to put the periods if anacronym you use is not that familiar withreaders.
Do you use two periods in a sentence ends in an abbreviation?
This one is simple enough: never double upperiods. If a statement ends with “etc.”the period in the abbreviation does doubleduty, serving as the full stop to end the sentence. If,however, you need another mark of punctuation after anabbreviation, you can put it after theperiod.