I read in a biography (Five Against One maybe?) that the recorded version is mostly phonetically appealing nonsense and that Vedder never wrote down the lyrics because of that.
I remember when YL was first released and how
huge that song was among the serious fans and songwriters who studied the band's output. I had a roommate in college who had the supposed lyrics hanging on the wall of his room and was around for more than one party in the '90s where someone would put it on and a hush would come over the entire room. It was a classic case of giving the audience just a little less than they wanted and whether that was by design or not, it's worked out very well. I have to imagine that at this point the band is just taking advantage of that idea.
I suppose that only the band knows for sure.
