Metadata & Validation

When using strict PDF/A profiles (Level A or UA), specific metadata fields become mandatory.

Mandatory Fields (E003)

If you select a strict profile but fail to provide required metadata, the system will verify compliance.

Profile	Required Fields	Behavior on Missing
PDF/A-UA1	title, language	E003 Error if title is missing.
PDF/A-1a/2a/3a	language	Auto-detected (see below).

WARNING

E003 Error: A large white box with red text will appear on the PDF listing missing fields (e.g., "Missing: title").

Language Auto-Detection

The metadata_language field is mandatory for accessible PDFs (Level A/UA). To simplify integration, xPdf employs a Smart Detection Policy:

1. Explicit: If you provide metadata_language (e.g., "en", "zh"), it is used.
2. Auto-Detect: If missing, we scan the document content:
   • Chinese characters -> zh
   • Japanese scripts -> ja
   • (Supports CJK, Arabic, Hebrew, etc.)
3. Fallback: If detection fails (e.g., only numbers/barcodes), it defaults to "und" (Undetermined).

NOTE

This means you generally do not need to manually set metadata_language to avoid errors. The system handles compliance automatically.