Parallel realization
The UN layout key
The United Nations Layout Key (UNLK, ISO 6422) is the standard A4 form for aligned trade documents: an image area of 183 × 280 mm on the layout-chart grid agreed with ISO 3535 — eight standard boxes across, 33 lines down. The directory’s bridges locate 254 elements on that grid by line and character position (L, P). Plotting them reconstructs the model form: the same data the directory carries, realized as the printed document.
Scroll or pinch to zoom, drag to pan — or focus the form and use the arrow keys, +/− and 0. Field tags appear at higher zoom.
Sections of the model form
133 distinct fields
254 elements carry a UNLK bridge; shared fields are the master-document principle at work — one box on the form serves every document derived from it.
How to read a location
L is the line on the form (1–33), P the character position within the line (1–82). A field spans both, e.g. an..17 at L 04, P 63–80: seventeen characters in eighteen positions on line 4 of the right-hand column.
Select a field to see the elements it carries. Sources: UNECE Recommendation No. 1 (ECE/TRADE/432E), ISO 6422, ISO 3535 — the document pages transcribe the directory’s own presentation rules.