Answering questions that may arise related to the meaning of portions of an IEEE standard concerning specific applications.

IEEE Standards Interpretation for IEEE Std 1003.1™-1990 IEEE Standard for Information Technology--Portable Operating System Interfaces (POSIX®)

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Interpretation Request #18
Topic: system documentation Relevant Sections:

(, p. 3, lines 85-88)
Do the words "unless the system documentation is explicitly mentioned" mean that documentation about a feature shall not be included in the PCD if it's required to be present in the system documentation? My reading is that this negates "shall appear in the conformance document", but does not negate the alternative, "may appear in the conformance document". Specific example: p. 44, lines 113-116. The system's interpretation of ARG_MAX must be specified in the system documentation. Does this mean that this interpretation shall not also be specified in the PCD? Related issue (may require a change to 1003.1): Where 1003.1 requires that information be provided in the system documentation, it should also require that a pointer to this information be provided in the PCD. Without such a requirement, assertions related to the system documentation are untestable. Testing them would require an exhaustive audit to find the information and verify that it's not contradicted elsewhere in the documentation.

Interpretation Response
a) Lines 85 to 88 mean that all instances of "shall document" in the standard place a requirement on an implementor of a POSIX conforming system to include in the POSIX Conformance Document a description of the referenced feature, unless this standard specifically requires it to appear in the system documentation.

Information required to be in system documentation may also be in the PCD, either as a reference to the system documentation or as a copy of the text. Whether in PCD or not, it must still be in system documentation.

The related issue is not addressed by the current standard.

Rationale for Interpretation
The POSIX Conformance Document need not be a component of or packaged with the System Documentation, so including a reference or section in the PCD alone is not sufficient.

Editorial note for future revision of standard (not part of the interpretation)
The related note should be considered in a future revision.