What manufacturing topic should Sierra explain more clearly?

PCB manufacturing has a lot of rules, tolerances, and processes that designers are expected to understand but they’re not always explained very well.

Soooo dear designers: what’s one manufacturing topic you wish Sierra explained more clearly?

Maybe it’s:

  • How your stack-up is actually built
  • What “minimum” trace/space really means
  • Via aspect ratios and annular rings
  • Controlled impedance
  • Why your fab flags certain things during DFM

Or something completely different??