Section 28 of 105
27. Normative Keywords
Stable section ID: S05-CON-014-SECTION-28 · 12 content blocks
- System05 shall use a controlled set of normative keywords.
- SHALL indicates a mandatory requirement.
- SHALL NOT indicates a mandatory prohibition.
- SHOULD indicates a recommended practice from which departure is permitted when justified.
- SHOULD NOT indicates a discouraged practice that may be used only with adequate justification.
- MAY indicates permission or an optional capability.
- CAN indicates physical, technical, or logical possibility and shall not create an obligation.
The keyword MUST should be reserved for unavoidable external legal requirements or logical necessities and should not be used as the normal System05 mandatory operator.
Normative meaning shall not depend solely on capitalization, bold formatting, color, or typography. Machine-readable records shall preserve the obligation class directly.
Words such as “appropriate,” “adequate,” “reasonable,” “sufficient,” “timely,” or “as necessary” shall not be used without criteria, referenced engineering judgment, or a defined decision authority.
Future tense using “will” shall not create a requirement.
Translations shall preserve normative strength. If exact equivalence is difficult, the controlled English version and the approved translation mapping shall identify the authoritative interpretation.