+Problem shape. An optional construct sits inside a name — a maiden clause, a trailing title — and the requirement is that writing it changes nothing else about the name. Checked after the fact, that invariant has to be defended at every place the construct can end, and each defense has to model what later stages would do to the words it gives up. Contract statement. Read the name as if the construct were not written, using the rule that reads that position, not the whole parse. The construct takes only what that reading leaves. Where later stages could still move what the reading decided, give those words their roles at the take so no later join can reach them. The invariant then holds by construction and is not a property each stop must defend. How it works. M2 before #601 scanned forward, stopped at suffix-looking words, and kept a release check asking at each stop whether the name left standing would read what was given up as post-nominals. That check modelled the P2 chain, the P5 bound join and P6's attachment, and #548 was it failing at the one stop that never asked. #601 replaced the stops and the check with the clause-free reading plus the bind: a net 689 lines out of `_group.py` (+210/−899 in the #601 commit), and #535's grids went from 15,586 and 8,713 invariant violations to 0 (prototype measurement, 2026-10-03, #601's comments). The first half already appears twice. H5's trailing title is TRANSPARENT: "what stands once the chain is taken reads exactly as it would read written without the title, plus the title". P3 asks its word count and its one-case question of the name's OWN words, so a clause beside the name changes neither. M2 is the first to bind as well, because its construct sits in front of the run it reads and the joins come later. Two limits, both measured on #601. Read with the TRAILING rule, not the full parse: a head the full parse reads differently (H1's lone title, a P5 join) would otherwise move where the construct ends. And binding means the run can read differently from the same words with no construct (`JANE Q. DOE GEB. LE DO DO` gives suffix `DO DO`, while the full parse of `JANE Q. DOE DO DO` chains them into the family), which rules.md#M2 accepts in so many words. Lives in. nameparser/_pipeline/_group.py (`_maiden_take`: the view, `tail_reading` over it, and the role-tagged pieces `group()` applies); nameparser/_pipeline/_pieces.py (`tail_reading`, H5's chain); the P3 own-word test in `_group.py`. Reach for it when. A rule is growing stops, exceptions or a release check whose job is to keep one construct from disturbing the rest of the name, and above all when that check has started to model another stage. Ask what the name reads as without the construct, and make that the rule.
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