Actually, it's incorrect.
= A contraction of "it is" (or "it has" when followed by a past participle).
= Third person singular neuter possessive pronoun (similar to "his" or "her," but for items that have no gender).
= Nothing. This word does not exist.
As a general rule, if the word can be replaced with "it is," it should have an apostrophe between the t and the s.
If the word cannot be replaced with "it is," it should not have an apostrophe.
At present, this thread title essentially reads "Rare stepping up it is game."
Not to get off topic or anything...