In November 2008, the User Requirements Notation (URN) was approved as Recommendation Z.151 by the Standardization Sec- tor of the International Telecommunication Union (ITU-T). URN is the first and currently only standard that supports both goal-oriented and scenario-based modeling for requirements engineering activities. The Aspect-oriented URN (AoURN) is a recent extension of URN that com- bines goals, scenarios, and aspects in one framework. AoURN is a can- didate for future versions of the URN standard. We first summarize the basic concepts and notation of AoURN and then discuss advanced fea- tures of AoURN that are necessary for large-scale modeling. Based on our experience with AoURN modeling, we present a list of requirements including rationale for an aspect-oriented extension of Z.151 that suc- cinctly expresses the required features to evolve URN into a complete aspect-oriented modeling framework.