>>32418185as
>>32418446 said, (You)s are just replies. People like to attract attention to themselves. I'm pretty sure i has to do with getting the replies to appear on the top (or bottom on mobile) of your post.
And for a better explanation using greentext is used for quoting in some way or referring to something someone else said. If you want to do internal-dislodge-esk things, try using spoiler tags instead. {spoiler} like this {/spoiler} but replace { } with [ ].
enjoy your (you) :^) 
