1. Requirement-Type Clauses

To express the requirements that need to be met, the modal verbs shown in Table 1 should be used.

2. Instruction-Type Clauses

In regulations or test methods, to express direct instructions, such as actions that need to be carried out, steps to be taken, etc., the imperative sentences shown in Table 2 should be used.

3. Recommendation-Type Clauses

To express recommendations or guidance, the modal verbs shown in Table 3 should be used. The affirmative forms are used to express the possible options recommended or the action steps considered particularly suitable, without the need to mention or exclude other possibilities. The negative forms are used to express that a certain possible option or action step is not the preferred one but is also not prohibited.

4. Permission-Type Clauses

To express permission, the modal verbs shown in Table 4 should be used.

5. Statement-Type Clauses

To express the abilities such as the aptitude, adaptability, or characteristics required to do or complete the specified matters, the modal verbs shown in Table 5 should be used.

To express the results caused by the expected or conceivable physical, physiological, or causal relationships, the modal verbs shown in Table 6 should be used.

General statements should be expressed using declarative sentences.