I just saw the following title at CNN's website:
"Green blunder costs England victory against U.S."
Green is the English goalkeeper, so my question is: shouldn't it be:
"Green's blunder costs England victory against U.S." instead ?

Another doubt with the apostrophe is about something I've seen a couple times. Let's say I'm going to a bar called Blue and invite my friends to come along. What is correct:
Meet me at Blue
Meet me at Blue's
I saw both forms and don't know which one is correct. If it's the second why do I need the apostrophe there ?

Thanks guys for your time.
Green blunder is OK-- it is headline English. (And YAAY, USA!)

If the bar's name is 'Blue', then 'Meet me at Blue'. If the owner's name is Blue, then 'Meet me at Blue's'. If you have actually seen both forms of this specific name, then someone is confused.
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What's the difference of being an headline ?
Headline English, and less obviously, newspaper English, is abbreviated in various ways. Articles and other function words are omitted from headlines, verb forms are simplified, unnecessary punctuation is omitted or the simplest options are chosen, etc.
How do you define 'unnecessary punctuation'?
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aph1234How do you define 'unnecessary punctuation'?
Punctuation that can be done away with leaving the text understandable.