<Snipped quote by Teknonick>
But for the player looking for RPs to join, does it really matter how much the GM wants new players? If it's open and they're interested in the RP, then it's open and they're interested in the RP. To them, it doesn't matter if the GM is looking for ten more players or just two.
Pretty much this. Open is open, if you're the person who needs more information about the exact state of openness, then read the thread. This is intended to be at-a-glance information, so it should be simple and clear about what it means. The fact that the question had to be posed about what the difference between the suggested tags implies that more than one player on RPG is going to question the same, misunderstand what Open and Recruiting mean, and miss a possible RP because of it.