Another way to look at it: Does the term "optional rule" mean anything?
Other RPGs (and even other versions of D&D) include optional rules; what could they mean by that? I always took it to mean, that an optional rule is a rule that is NOT in effect unless the DM specifically says it IS, as opposed to the regular rules, which ARE in effect unless the DM says they're NOT.
By this definition, the using the MM races for PCs is an optional rule even though the text doesn't actually use the term "optional rule" (because the text does say that the DM has to specifically allow them, instead of specifically disallowing them, which is the definition of an optional rule).
-- 77IM
Other RPGs (and even other versions of D&D) include optional rules; what could they mean by that? I always took it to mean, that an optional rule is a rule that is NOT in effect unless the DM specifically says it IS, as opposed to the regular rules, which ARE in effect unless the DM says they're NOT.
By this definition, the using the MM races for PCs is an optional rule even though the text doesn't actually use the term "optional rule" (because the text does say that the DM has to specifically allow them, instead of specifically disallowing them, which is the definition of an optional rule).
-- 77IM