Apostrophe + "s" after the letter "s"

[SurreyGuy]

Is it correct to use an apostrophe plus "s" after a name that ends in "s"?

For example, which is correct :

Charles' hair is blonde OR Charles's hair is blonde?

T.I.A.

[THECORBYLOON]

I use blond for male, blonde for females, I use the hyphen in to-day, to-night & to-morrow and I write 'phone wi an apostrophe.

[Quizmonster]

And with without its th, TCL...and yes, I do know why you do that! Just another example of what I wrote earlier; namely, that everyone is perfectly free to use English as they see fit.
The point is, however, that these little personal idiosyncrasies - blond/blonde, wi, to-day etc - are just that...both personal and idiosyncratic.
When someone asks a question here on AnswerBank, however, I myself always assume that they want to hear the general truth of the matter...ie the truth as revealed by authoritative sources such as the OED...and not some outdated or just plain wrong explanation.
Cheers to both of you.

[SurreyGuy]

I'm currently reading a book by Tess Gerritsen and she refers to a woman as having blond (no "e") hair.

[Quizmonster]

Well, there you go, SG! Even more evidence that the words are not - and never have been - gender-specific, as I've already said.