"Each calendar year, foal names must begin with specific letters of the alphabet as designated by the KFPS. Names should be relatively simple, ideally consisting of a single word. Farm names or initials are not allowed to precede a name, but may follow the name if approved by the KFPS. Names do not have to be Dutch." "The naming system using designated letters each year has been in place for many years. By using letters for each year, it is easier to identify when the horse was born. The names often are Dutch in origin, and can be a single word or even include farm initials or names, only after the given name of the foal." - FHANA
Here's a look at the next several year's designated letters for naming Friesians per the KFPS:
2022: T, U, V 2023: W, X, Y, 2024: A, B, C 2025: D, E, F 2026: G, H, I 2027: J, K, L 2028: M, N, O 2029: P, Q, R, S