Reviewing the normative evidence, this chapter argues that Carolingian reformers of the early ninth century did not, as is commonly assumed, create two homogeneous 'cohorts' of female religious. Instead, they showed female religious, their associates and their patrons where lay the outer boundaries of legitimate experimentation, allowing for a great deal of variation between individual communities. To make these points it considers, in order, the decrees of the Aachen reform synods of the 816 decrees, the context in which they originated, their impact on subsequent prescriptive and legislative texts, and finally their reception in female religious contexts. These observations allow reassessing, in chapters 2 and 3, the concrete situation of female communities in ninth- and early-tenth-century Lotharingia.