We won't know until we know ;)
But I'm thinking along the lines of an acronym. Very common, but also hard to find if you don't already know it. Medieval people loved mottoes and anagrams.
I had a boss who used to write /AMDG after his signature. It stands for Ad maiorem dei gloriam (For the greater glory of God). Obviously he went to a Jesuit school.
I have friends who have rings that say LEO (Labora Est Ora, Work is Prayer), AUECUID (Anima una et cor unum in Deum, One heart and soul in God), and LJCSOGHMUU (Lord Jesus Christ, Son of God, have mercy upon us),
My dad had a Masonic ring with a Latin acronym, but I can't remember what it was. I almost think it might have been SDG (Soli Deo Gloria, Glory to God alone). When I was a kid I thought it was someone's initials.
I've seen many similar pieces. Too many to remember them all. I remember one that had a Latin acronym for "Let there be light", and another for "In the beginning what was Word", and another with a French acronym for Make haste to help me, Oh Lord.
I would not have guessed any of these by myself. Someone had to tell me. I think it might be the same with this sword. Someone who knows the acronym already will see it and recognize it. Until then we'll all keep guessing.