This paper centers on the problem of transparency in Romance metaphony patterns, wherein a post-tonic high vowel triggers height assimilation in a stressed vowel. Two patterns are contrasted involving words with antepenultimate stress: systems that show height assimilation across a transparent penult and systems that exhibit harmony in both an intervening penult vowel and the stressed antepenult. A two-fold proposal is made. First, it is argued that metaphony is driven by a licensing constraint which requires that marked structure be associated with a strong position. In metaphony, the high, unstressed vowel is marked by virtue of its perceptual difficulty. Second, a generalized licensing constraint formulation is proposed, under which licensing is satisfied by various configurations. These include direct licensing and indirect licensing configurations (Steriade 1995), and also a new configuration, termed identity licensing, in which marked structure in a weak position is licensed through a correspondent in a strong position. Identity licensing maintains strict segmental locality (Ni Chiosain & Padgett 2001) by positing a copied feature in forms showing assimilation across a transparent penult vowel. Applications of the generalized licensing approach to the Asturian Lena Bable and Nalon Valley varieties and the Cantabrian Tudanca variety are discussed.