But if I say "Help me, mom!" I could be referring to her by title, and that title might not even be unique since one could have multiple moms. In that case, the

But if I say "Help me, mom!" I could be referring to her by title, and that title might not even be unique since one could have multiple moms. In that case, the ambiguity makes me feel like the lowercase should be preferred for its broader applicability, unless trying to make some point.