Membership
The Order of the Shamrock is for people formerly recognised as Chief of the Name, but who are no longer due to the discovery of the existence of a more senior claimant. In other words: "If it is found that there is a more senior claimant while your are filling the position, then at the end of the year the more senior claimant will begin to fill the position. However, displaced chiefs and chieftains will become Knights of the Order of the Shamrock, and will hopefully be granted the opportunity to be advisors or stewards to the new titleholder." However, the person in question must still be in good standing with the Head of the Royal Family.
The Order of the Shamrock has no member limit. The post-nominals are R.S. for "Ridire an Sheamróig" which is Irish for "Knight of the Shamrock."