To design equitable assessment systems, we focused on range. By expanding the range of learners, the range of teachers and the range of classroom contexts we considered since Day 1, we ensure that diversity was supported through flexible structures. In this post, designing "to a T" refers to the meticulous, nuanced work involved. It also refers to three "T's" -- an expanded timeframe for assessment horizons, attention to task design, and the preservation of teaching time in classrooms. To care about equity is to act, and comprehensive, equitable, yet realistic designs don't engineer themselves. Balance and symmetry also find their way into this third post about our assessment system.