"You'll never walk alone" is of course in the folk tradition, even by Jim's rather narrow interpretation. The Anfield rendition allows the song to go down in folklore for many years to come.

Back to the original question, that deserves better than preaching by someone who thinks a meeting in 1954 trumps err.. the evolving folk tradition. (That's irony, that is you know. My mate knows a lot about irony. One day he'll tell me what it means.)

To become a standard (almost as subjective a term as folk itself) you need it to be assumed to be Oirish. Even better if Christy Moore is generally seen as writing it.