Biliterals are hieroglyphs which were substituted in place of pairs of alphabet characters. The sound of the biliteral hieroglyph is the same as the sound of the the alphabet characters it replaces. Biliterals 'streamline' writings by eliminating large numbers of simpler characters.

Here are a few examples of biliterals:

HIEROGLYPH	COMBINES	PRONOUNCED
	+	gm
	+	kha
	+	wen
	+	wep
	+	djed
	+	ges
	+	hen
	+	neb
	+	adj