The Rangers F.C. Hall of Fame is a list established in 2000 by the then Rangers chairman, Sir David Murray, the first of any club in Britain.
He decided that the club should remember and honour the achievements and contribution made to Rangers by its finest players throughout its history. A mahogany panel above the famous marble staircase was assigned to display the names of those former players inducted into the Hall of Fame and an annual presentation ceremony was instigated where the players honoured received their award.
Various criteria are considered by the panel when selecting new members: including the individual's service to the club, the number of appearances made, the honours and international caps won whilst with the club, and the players exceptional ability.
The first member elected was Moses McNeil, one of the founders of Rangers and there are now over 100 Hall of Fame members in total.
You can find a full list of those inducted via this Wikipedia article.