Why statement identifiers are never reused

A statement identifier is permanent from the moment it is published. It is never renumbered, never reused for a different competence, and resolves for as long as the framework exists. This is the most boring commitment in the specification and probably the most important.

What reuse would do

A credential awarded in 2027 cites a set of identifiers. Its coverage map, its certificate and possibly its regulatory filings all refer to them. If we later reuse one of those identifiers for a different competence, every one of those documents now claims something nobody asserted, and there is no way for a reader in 2031 to tell.

Renumbering for tidiness has the same effect and is more tempting, because it usually happens during a reorganisation that feels like an improvement. A gap in a numbering sequence is not a defect; it is evidence that something was deprecated rather than quietly overwritten.

How change happens instead

A statement whose meaning changes is deprecated and a new identifier carries the new meaning. The deprecated identifier stays published permanently, marked, pointing at its successor where there is one. A reader following an old citation reaches a page that tells them what happened rather than a 404 or, worse, a different competence wearing the same number.

Editorial corrections — a typo, a broken cross-reference, a clarified indicator that does not change what is being asserted — are made in place and published as a dated correction. The test is whether an assessor would judge a candidate differently. If they would, it is a new identifier.