Welcome to the Grammar Minute, where we’re saving the English language sixty seconds at a time! I’m Lauren Smyth, back with a somewhat obscure rule from the Chicago Manual of Style. My favorite—AP doesn’t even hold a candle to it. But that’s beside the point. When you’re abbreviating United States as US, do you put periods after the letters or not?
According to the Chicago Manual of Style—which is much easier to abbreviate CMOS—you don’t need periods in two-letter abbreviations unless that abbreviation is for a person’s name, like W. B. Yeates. US and UK are two common examples where people like to put the periods after the letters, but they aren’t necessary.
As a side note, when you are abbreviating a name, there should also be a space between the two abbreviated letter. W-period-space-B-period-space Yeates. And again, all this is for CMOS specifically. Other style guides may have different rules.
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