Method · casefile v2
The system separates legal and factual selection from language drafting. Each stage has a narrow job and a fail-closed check.
1 · Structured answers
Email, optional letter identifiers, operator, site and land type, notice route and content flags, dates, amount, driver or keeper position, selected circumstances, available evidence and stage. Free text is limited; a possible-PII warning does not block submission.
2 · Deterministic ground selection
The engine checks the paragraph 9 day 1–14 window or paragraph 8 day 29–56 window, applies the second-working-day delivery presumption when needed, limits keeper-liability grounds to supported keeper cases, and marks every candidate included, needs evidence or not used. Unknown dates never become an asserted breach.
3 · Citation allow-list
Each active ground receives citation identifiers from a versioned allow-list. The drafting model receives only the case JSON and the matching source snippets. An unapproved legal citation causes rejection.
4 · Language draft
The model returns structured JSON sections: salutation, introduction, one argument and evidence request per selected ground, and closing. Headings, source labels and any empty personal placeholders are added deterministically. Operator statistics never enter the letter.
5 · Automated checks
The validator checks the JSON shape, selected-ground count, citation allow-list, restricted claims, keeper and amount rules, placeholders and a 450–800 word assembled letter. It allows one repair pass; if that does not pass, checkout is not created.
Reference regime
Law and code references checked on 6 September 2026: Private Parking Sector Single Code of Practice v1.1 (in force 17 February 2025; foreword updated 13 April 2026); the statutory Code under the Parking (Code of Practice) Act 2019 is not in force at this date.