# signatures/documents

## Purpose

Registers magic-byte signatures for document and data format files with the global signature registry. Covers office documents, structured data, e-books, and markup formats. Each signature is registered as a side effect of importing this module.

## Features

- PDF (`%PDF` header)
- Microsoft Office legacy formats (DOC, XLS, PPT — OLE2 container `D0 CF 11 E0`)
- EPUB (ZIP-based e-book container)
- Rich Text Format (RTF)
- SQLite database (`SQLite format 3`)
- Apple Pages, Numbers, Keynote (ZIP-based, detected via content sniffing)
- JSON lines and CBOR (RFC 7049) binary format
- Protocol Buffers wire format heuristic

## Usage

```typescript
import "@suaveplan/mime/detection/from-magic-bytes/signatures/documents";
import { detectFromMagicBytes } from "@suaveplan/mime/detection/from-magic-bytes/from-magic-bytes";

const pdfBytes = new Uint8Array([0x25, 0x50, 0x44, 0x46, 0x2d]); // "%PDF-"
console.log(detectFromMagicBytes(pdfBytes)?.mime); // "application/pdf"
```

## API Reference

No exported functions. All signatures are registered via `registerSignature` side effects.

## Implementation Notes

OLE2 Compound Document Format is the container for legacy Microsoft Office files (pre-2007 DOC/XLS/PPT). The magic bytes `D0 CF 11 E0` identify the OLE2 container but not the specific Office application — the detector returns `application/vnd.ms-office` as a generic fallback. Modern Office formats (DOCX, XLSX, PPTX) use the ZIP container and are handled in the archives signatures module.

### Coverage

The document signature set covers PDF (`%PDF`), Microsoft CFB-backed legacy Office (`D0 CF 11 E0 A1 B1 1A E1`), OOXML (`PK` with `[Content_Types].xml` entry — priority 105 so it beats plain ZIP), ODF, RTF (`{\\rtf`), PostScript (`%!PS`), EPUB (ZIP with `mimetype` = `application/epub+zip`), and MOBI/AZW. The 105 priority on container-based formats is critical: without it OOXML would match plain ZIP at 100 and lose granularity.