A closed list of categories reads like a filing convenience. It is not. Every entry has to take exactly one, so the list is the answer to “what is this project about” — written down in a config file, usually by someone solving a smaller problem, and thereafter binding on everything.
That is fine, and it is better than the alternative of an unbounded list that decides nothing. The hazard is that the decision becomes invisible. Nobody re-reads a vocabulary; they read the entries that use it. So a subject the list cannot express does not produce an error or an argument — it produces nothing, and the absence is indistinguishable from nobody having got round to it.
The practical test is worth stating, because it converts a vague sense of scope into a checkable question: if a claim arrived tomorrow with excellent evidence and no category to take, would you add a category or decline the claim? An honest answer to that is the scope, and it is usually more specific than anyone would have said out loud.
Applied here, and this project is its own worked example twice over.
The two schemes carry different vocabularies. Read one way, that arrangement said: the reading list holds vision, generative and theory work, the recommendations hold seven topics none of which is about vision, so a vision paper can be a note and cannot be a recommendation — not on judgement, not on evidence, but because there is no category for it to take. The recommendations are scoped to language-model training by construction, which nobody had written down.
That reading was load-bearing for about a year and it was wrong, in both
directions at once. It was too narrow: two Active serving practices were
already sitting outside it and nobody noticed, which is this principle’s own
warning about vocabularies working in the dark. And it was too broad: it
declined work whose transferable content — a preconditioning scheme, an
annotation bootstrap — is exactly the kind of claim the seven topics exist to
hold, so the scope was making the record ignorant of its own subject.
The repair is the corollary below, taken seriously. ADR-026 — superseding ADR-020, whose decision it carries forward — scopes the recommendations by the kind of claim, so that where a technique was discovered stops deciding whether it can be recommended. Read that decision, not this paragraph, for what the scope now is.
The corollary: because it is a decision, it can be revisited — but only deliberately, by changing the vocabulary, and never by one entry quietly taking a tag that does not fit. A category added to admit a single document is how a scope stops being one.
The mechanism this principle warns about is now gone for this pair
ADR-026 went further than the repair above and gave the practice
registry the same thirteen topics the reading list has. So the arrangement
that made this a worked example — two vocabularies, one narrower, the gap
between them silently encoding a scope — no longer exists here. No LIT
tag can read as a scope boundary, because every one of them is a word a
practice can carry.
That decision adds two categories admitting no documents at all, which is
worth holding against the corollary directly. It passes, and the reason is the
distinction the corollary is drawing. What it forbids is widening a scope by
the back door, one entry at a time, to avoid making the decision — a category
bent to fit a document somebody wanted in. ADR-026 makes the decision in
the open and admits nothing: everything now admissible was already admissible
under ADR-020, by kind of claim. The vocabulary caught up with a scope that
had already changed, rather than a scope changing because a vocabulary did.
The principle survives its own application intact, and gains a sharper test from it: ask whether the category was added because a decision was made, or so that one would not have to be.