Another angle is that HR requires that a public posting be created for N weeks for all new positions, but there's someone they really want to hire internally. S

Another angle is that HR requires that a public posting be created for N weeks for all new positions, but there's someone they really want to hire internally. So the post is crafted such that only the internal hire meets all of the requirements, and they can just reject everyone else. I've seen it done. A friend of mine was one such internal transfer, and before that, he helped write the hiring post for converting a contractor to full time.