A label is scanned, so a symbol must never read as something other than the value it was given. Record values are untrusted and stay out of every diagnostic and exception. - No value, literal or bound, may hold the two characters an escape of the encoder begins with. \<FNC1> in a plain Code 128 value drew a GS1-128 of the record's choosing, \<FNC3> set the reader-programming flag, and QR dropped the escape. Refused in every symbology, with a count only. - Interleaved 2 of 5 of an odd number of digits is refused, not padded. - EAN and UPC values are the whole number with its check digit, which is verified; a shorter number is refused, never completed or padded. - The check digit of every GS1 key in a gs1-128 element string is verified: the identifiers the GS1 Syntax Dictionary marks, as the bundled Zint carries it. - VALUE_NOT_ENCODABLE joins the errors for these and for a value a symbology cannot hold; SCENE_INVALID is no longer used for a value. A symbol of more modules than the encoder draws is BARCODE_DOES_NOT_FIT. - Quiet zones and the smallest module are a table by symbology (scene2/barcode/Symbology), each number with its source. barcodeProfile names the rule: none, gs1-general or gs1-logistics; not stated, the strictest written for the symbology. A GS1-128 is so held to 0.495 mm unless its scene says otherwise, at which a GTIN with a date and a serial number fits no label 4 in wide. - The bars of a linear symbol must be as tall as its symbology asks, and the height is part of the fit. minHeight overrides, with the standing warning BARCODE_HEIGHT_BELOW_RECOMMENDED. - QUIET_ZONE_INTRUDED is an error: an element later in the list whose ink would enter a symbol or its quiet zones is refused, when a scene is validated as when it is rendered. - A barcode sits in the middle of its box unless the scene says otherwise. - A bound barcode takes maxLength and is proven at validation in a linear symbology. FIT_NOT_PROVEN stays for no length and for two-dimensional symbols, whose encoders have no largest symbol of a length. Codes and property names are added in one change: foundation's FailureCode and warning set, the preview's sentences, the bridge's accepted refusals and schema vocabulary, the renderer's vocabulary and the schema. The three barcode goldens are unchanged byte for byte; barcode-retail is new. Co-Authored-By: Claude Fable 5.2 <noreply@anthropic.com>