The piece notation you gave for the pieces might be what the Alfaerie Many set is using for these piece images, but within the context of the game itself, it is not suitable notation. Also, Game Courier can support aliases, and it now supports custom piece sets as well. So, Game Courier is not forcing you to use such notation, and it's best to not impose this kind of notation on your readers.
The piece notation you gave for the pieces might be what the Alfaerie Many set is using for these piece images, but within the context of the game itself, it is not suitable notation. Also, Game Courier can support aliases, and it now supports custom piece sets as well. So, Game Courier is not forcing you to use such notation, and it's best to not impose this kind of notation on your readers.