I think every witch should have a section in their BOS dedicated to creating a family alphabet. (im not telling anyone this is just my opinion fell free to not add it) a family alphabet is an alphabet created with symbols as symbol as (-) or as hard as hieroglyphics. this alphabet should not be given to anyone out side of you family/ family coven.
a family alphabet is used to send messages and spells to one and another with out the worry that some one could see it. (I am a strong believer in privet collections of spells and rituals).
in the BOS the spells and rituals you don't want you family giving out, or the spell/ritual is a personal family one that only family members can see you just write them in the alphabet.
i hope to pass my alphabet on to later generations
if you have any questions fell free to message me or leave a comment.