5.4 Validation
5.4.1 Every reference resolves #
A published book MUST NOT contain a reference that does not resolve. A reference to a chapter, article, or appendix that does not exist is an error, not a cosmetic defect: it is indistinguishable, to a reader, from a reference to something that was deleted.
5.4.2 Checking #
Because section numbers are positional (§5.1), any structural change invalidates references — including references from other books, which the author making the change is least likely to be looking at.
After a structural change, an author SHOULD:
- Build the affected books and extract the actual chapter and article numbering from the rendered index.
- Collect every
§reference in the corpus. - Check each against that numbering.
Steps 1 to 3 are mechanical and worth automating. What is not mechanical
is whether a reference that still resolves still means what the citing
text implies. A reference to "the ordering rules of PSPU §5.6"
resolves happily after that article is rewritten to cover something
else.
5.4.3 Two traps #
Line-wrapped references. A citation split across a line break — the
book's short name at the end of one line and the § number at the start
of the next — is easy for a checker to miss and easy for an author to
introduce.
Appendix forms. A chapter appendix and a book appendix take different forms (§5.1), and a reference using the wrong one resolves to nothing — or worse, to something.