Though much time may be spent writing code in the C, C#, PHP, or Java languages, there comes a time when you need to hack English. Call it E.
It's a language with more rules than any programming language (I don't actually know this, but I imagine it's true. And as we all know if you imagine something, it can be true). To compound things, the debugging tools are scarce and weak.
In this realm, Kernighan and Richie's C is replaced with another concise tome, Strunk and White's Elements of Style.
I was in my editor looking at the following line of code:
As in Charles and Ray Eames' 1977 film, Powers of 10
I couldn't tell if it would compile. My only debugging tool was Word, which highlighted the term Eames and suggested Eaves, as in I ain't been droppin' no eaves, sir. Useless.
I proceeded to RTFM. The rule is that you add 's to a possessive singular noun, whatever the ending consonant. For plural possessives, you add a ' after the s, unless the noun doesn't end in s, in which case you add 's to the ending.