The Order of the Harp
The Order of the Harp was founded by His Royal Highness Prince Díolún on 29 April, 2019. It is, of course, named after the harp that is its symbol, and is also a symbol of the Gaelic people(s).
The Order of the Harp is perhaps the most selective in its membership selection. It is limited to 13 living members, who are unquestionably of absolutely zero royal or noble blood, and that the head of the claim, in this case Prince Díolún, considers friends.
The post-nominals for the Order of the Harp are R.C. for "Ridire an Chláirseach" which is Irish for "Knight of the Harp."