[Wikipedia-l] It's about its

[Poor, Edmund W]

Most of us can readily apply the following two rules:
* to show possession, it's correct to use: its
* we may change "it is" to its contraction: it's

So, I would like to be able to search for instances of:

   it's

...so I can check whether it's being used as a contraction for "it is" (correct) or as a possessive (incorrect: change to "its").

But when I tried to use Wikipedia search, entering: 

   it\'s

I got a bunch of articles with the following 2 characters highlighted in red:

   's

...which is a superset of what I want.

What is the correct search string to enter? 

Ed Poor