In the same way, use in the CSA B44 “Basic safety Code for Elevators and Escalators” is mandated by the NBCC, but is just referenced in a non-obligatory Appendix B Notes on Principles of Area 38 in the CE Code. Occasionally, specified requirements are referenced only in explanatory Appendix B https://tourismagency42952.blogoxo.com/35554857/the-basic-principles-of-electrical-design-compliance