Minimum length of load-bearing walls (shear walls)

Some people summarize the rule as "load-bearing walls need to be at least 60 cm." That's misleading, so I want to explain.

This book is the bible of wooden structural calculation for houses, and I believe every practitioner of structural calculation references it. It states the following:

• For bracing-type load-bearing walls: column pitch ≥ 90 cm, and floor-to-floor height ≤ 315 cm.
• For sheathing-type (plywood etc.) load-bearing walls: column pitch ≥ 60 cm, and floor-to-floor height ≤ 300 cm.

The minimum column pitch differs between bracing and sheathing walls. Floor-to-floor height is constrained by the column pitch. The book also notes that, for allowable stress design, the wall multiplier is capped at 7.

Some practitioners just let the calculation software do the work — this is where to be careful.