Producer name: use the form on the label (e.g. "Château Margaux" not "Margaux"). The ID is auto-generated as a URL-safe slug of producer + wine + vintage.
Vintage: four-digit year, or NV for non-vintage (mostly Champagne).
Adding a new region or grape? The dropdowns only show regions and grapes already in the codex. To add a new one, edit regions.json (add lat/lng) or grapes.json first, then return here.