In my few days here in the forum I've come to notice an abbreviation (OP) by the side of the name of some members, it might seems embarrassing that I don't know what it mean but we learn every day, and I believe that there are still new members that still don't know what OP mean as well, so if you have an idea you can go ahead and give a hint about it.
OP, Original poster or Owner of a post, just like you've rightly said, it's placed after the name of some persons, this is In a way to make members easily identify the one who made the post amongst other commenters.