English question

[KukriKhan]

Not at all. That rule you cite is correct, for indicating possession.

But technically 's is not a suffix (here's a list of english suffixes from wikiP
http://en.wikipedia.org/wiki/List_of_English_suffixes

But, I admit, 's operates much like a suffix (it modifies the base word).

Where the confusion comes in, I think, is that we also use 'suffix' to mean those modifiers we use for computer files. For example: .com .doc .txt

So non-native english speakers see that precedent, and logically apply it to written grammar rules. English is So-o-o-o not logical. Sorry.