More fundamentally, why is bracketing, both in the linguistic representation and in the metrical pattern, a necessary ingredient of metrical form? The answer to this question, if ever found, will form a central part of the theory of universal metrics. Bruce Hayes (1989: 258) French and Italian decasyllabic meters include obligatory constraints on the placement of caesuras. The English iambic pentameter is historically modeled on these meters, but does not overtly share these constraints. However, choices about caesura placement do have profound aesthetic effects in English poetry, and conformity to the Romance constraints is statistically significant (Duffell 2000). Here I suggest that properly formalizing the Romance constraints illuminates their formal role in English. First, I propose that the universal theory of poetic meter in Hanson & Kiparsky (1996) incorporate a family of metrical constraints parallel to the general alignment constraints which have been posited for grammar (McCarthy & Prince 1993). Then I revisit the longstanding question of why English poets allow exceptions to their meter’s cardinal rule on stress placement specifically for initial syllables, and suggest that the Romance constraints persist covertly as the conditions licencing these exceptions, precisely because the exceptions and the constraints accomplish a common end of signalling metrical boundaries. In this way, exceptions Hayes (1989) attributes to a general aesthetic tendency to allow beginnings to be lax may be grounded more directly in grammar.