Strunk and White says "Charles's" is correct -- is this still the case? [duplicate]

Solution 1:

It's down to personal preference -- but the modern convention, in my opinion, is to omit the final s. I'd always advocate omitting the final s because it's simply unnecessary: the apostrophe, by itself, clearly denotes possession. Whether or not American English adopts this is another matter...

But with British usage, it can often be quite erratic and anachronistic. A typical example is when I get on the London underground every day (the Piccadilly line going eastwards). One stop is called Baron's Court and its immediate neighbour is Earls Court.

You also get this with particular brands who choose to omit the apostrophe for clarity (like Twinings, and Waterstone's has announced it's dropping its apostrophe soon). So, in modern usage, the general trend is to omit the apostrophe. Another convention I've worked a lot with (MHRA's -- which I only use in academic essays) chooses to use the additional s for singular possession, and omit it for plural possession; so, for example: the boss’s daughter and the bosses’ daughters.

To answer Henry's point, there is no debate over 'St' and 'St.'. Because St James' Park refers to Saint James, the use of St is a contraction. You put a full-stop after an abbreviation (like Prof.), but you never put a full-stop after a contraction because the final letter of the abbreviated form is the same as the final letter of the full form (which is why you see Mr, St, Mrs, etc.)

Solution 2:

Those examples are fine in my opinion, though preferences vary. A classic example in England is

• St James's Park in London
• St James' Park in Newcastle
• St James Park in Exeter

And then there is the debate over St and St..