Content is self-contained
Capture the information itself; never defer to an external source for it. Attribution citations are fine; the only learning pointers are cross-references.
A wskill must stand on its own. The forbidden move is the deferral — sending the reader to an outside source for the substance instead of capturing it here, where it can't be projected or kept current. The validator flags the common phrasings. Attribution for credit ("per RFC 9110", "as POSIX specifies") is welcome where it matters. Pointers to further learning are expressed only as wskill cross-reference blocks to other wskills (possibly planned stubs), never as bare URLs in prose. Content is declarative reference data written to be projected: factual and lean, with the templates supplying presentation.
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