Getting confused about the difference between ‘shall’ and ‘should’? This chapter tells you how to understand provisions in the PNS. We convey the following provisions using these corresponding verbal expressions:

Requirements: SHALL or SHALL NOT

Recommendations: SHOULD or SHOULD NOT

Permission: MAY or MAY NOT

Possibility: CAN or CANNOT

The term “must” is used to express external constraints, commonly in technical regulations. It is not an alternative to “shall” to express requirements and should not be used in standards.

Want to dissect PNS/BAFS further? Follow @Bureau of Agriculture and Fisheries Standards and stay tuned for our next PNS ANATOMY Chapter!