Prose is not behavior

A check we run over one of our own sites reported that a file was shipping a font-loading setting the design foundation forbids. It was not. The file contained a comment explaining why that setting is forbidden and what it uses instead. The pattern matched the explanation, the check had no way to tell an explanation from an instruction, and the only thing wrong with that file was that somebody had taken the trouble to write down why it was right.

The repair was small and the doctrine attached to it was not. Comments are now stripped before matching, and any check whose pattern could plausibly appear in an explanation reads the source with the prose removed rather than the raw text. The comment recording the incident states the rule in four words, that prose is not behavior, which is worth more than the four lines of code underneath it, because the four lines fix one check and the four words fix the next fifty.

The mechanism is the distinction between using a term and mentioning it, which philosophy of language settled long ago and most tooling has never encountered, and it bites here because a regular expression matches a run of characters with no access to whether that run is doing something or describing something, so a scanner reading raw text charges the same penalty for committing a fault and for documenting its avoidance. Quine gave the distinction its formal treatment in 1940 and the practical version is older than any of us: the word poison on a bottle and the word poison in a sentence about bottles are not the same object, and only one of them will hurt you.

The failure has a famous public ancestor. In 1996 a profanity filter refused to register residents of Scunthorpe, an English town whose name contains an obscenity as a substring, and the pattern has recurred so reliably since that the town’s name became the standard label for it. Every instance is the same error wearing local clothes. The matcher sees the string and has no access to the situation, and the situation is the whole question.

What makes the cost more than an annoyance is the discipline sitting next to it. That same site requires that any change altering rendered appearance append a dated ruling to a ledger in the same commit, with framework-level rules amended in the shared design authority as well. The codebase is under an obligation to explain itself. Put a naive scanner beside that obligation and the two rules argue: the more thoroughly a file records what it rejected and why, the more surface it offers to be misread, and the cheapest way for a team to stay green is to stop writing the reasons down. Call it the explanation tax. Nobody decides to pay it. It is learned, one false positive at a time.

Which is the same requirement this corpus already argues for a different structure. A tradition that keeps its rejected opinions with their reasoning can reopen a question it once closed wrongly, and preserved dissent is the mechanism by which any collective structure revises itself. A codebase is one of those structures, its comments are where its dissents live, and a check that penalizes a recorded rejection is a system charging its own memory rent. Honest checks read the source and leave the reasons alone, which costs four lines and buys a codebase still willing to tell you what it decided against.