Ranes
Adventurer
I've been away for a couple of days but wanted to respond to this.
Of course an apostrophe can denote missing characters but you get into a mess when you apply that usage to abbreviations. Historically, abbreviations required full stops (periods, if you prefer). N.P.C. would once have been the correct way to write that abbreviation. Apostrophes would not have been used to denote missing characters (there was never a time when N'P'C's would have been correct). Now, even use of periods in such circumstances is generally considered archaic; even ie, eg and etc no longer demand their usage.
Abbreviated words like phone, for telephone, would have been given an apostrophe, thus: 'phone. We don't do it any more, thank goodness (in fact, such usage was always rare, even in formal, academic application). Outside their use in denoting possessives, apostrophes now only denote letters missed in concatonation, where two words are conjoined and certain letters omitted, as you illustrated with your own examples. Using them in abbreviations just muddies the waters. You said it yourself; you are forced to justify the existence of the apostrophe by context. Even then, the rule you're applying doesn't make much sense. An apostrophe can be used to denote characters missing from the last word of an abbreviated phrase? I don't think so and I would defy anyone to point to a house style guide in use anywhere that says otherwise. (Pointing me in the direction of semi-literate marketing materials doesn't count.)
An apostrophe denotes possession or omission. In the word "can't", the apostrophe stands for the missing letters "no" in "cannot". In the same way, the apostrophe "s" after an initialisation can represent the omitted letters between the capital and the terminal "s". So in the case of "NPC's", the apostrophe can be a substitution for the missing letters in "Characters".
Of course an apostrophe can denote missing characters but you get into a mess when you apply that usage to abbreviations. Historically, abbreviations required full stops (periods, if you prefer). N.P.C. would once have been the correct way to write that abbreviation. Apostrophes would not have been used to denote missing characters (there was never a time when N'P'C's would have been correct). Now, even use of periods in such circumstances is generally considered archaic; even ie, eg and etc no longer demand their usage.
Abbreviated words like phone, for telephone, would have been given an apostrophe, thus: 'phone. We don't do it any more, thank goodness (in fact, such usage was always rare, even in formal, academic application). Outside their use in denoting possessives, apostrophes now only denote letters missed in concatonation, where two words are conjoined and certain letters omitted, as you illustrated with your own examples. Using them in abbreviations just muddies the waters. You said it yourself; you are forced to justify the existence of the apostrophe by context. Even then, the rule you're applying doesn't make much sense. An apostrophe can be used to denote characters missing from the last word of an abbreviated phrase? I don't think so and I would defy anyone to point to a house style guide in use anywhere that says otherwise. (Pointing me in the direction of semi-literate marketing materials doesn't count.)