In the PDF file structure, named destinations are stored in the document catalogue — the root dictionary of every PDF. Specifically, they are stored in the <strong>/Names</strong> dictionary under a <strong>/Dests</strong> name tree.

A name tree is an efficient binary-tree-like structure for mapping string keys to arbitrary PDF objects. Each entry maps a destination name (a string like `"chapter-3"` or `"fig-12"`) to a destination array that specifies:

1. The target page (as an indirect reference to the page dictionary) 2. The fit type — how to fit the view when jumping to the destination 3. Additional parameters for the fit type (coordinates, zoom factor)

Fit types include: - <strong>/XYZ</strong> — Jump to x, y coordinates at a specified zoom. The most common type. - <strong>/Fit</strong> — Fit the entire page in the window - <strong>/FitH</strong> — Fit the page width, scrolling to y coordinate - <strong>/FitV</strong> — Fit the page height, scrolling to x coordinate - <strong>/FitR</strong> — Fit a specific rectangle in the window

A GoTo action (the PDF action type for internal navigation) can reference a named destination by name using the `/D` key:

``` << /Type /Action /S /GoTo /D (chapter-3) % reference by name >> ```

Or it can reference a destination directly (without a name):

``` << /Type /Action /S /GoTo /D [42 0 R /XYZ 0 700 1.5] % page 43, y=700, zoom=1.5x >> ```

The named version is portable — the destination can be updated independently of the action that references it.

PDF supports two ways to specify where a link or bookmark should navigate:

**Explicit destination** — The destination array (page, fit type, coordinates) is embedded directly in the action or bookmark. Simple and direct, but if pages are renumbered or content moved, the link points to the wrong place.

**Named destination** — The destination array is stored under a symbolic name in the /Names dictionary. Links and bookmarks reference the name, not the array directly. This allows destinations to be updated in one place, and the change propagates to all links that reference that name.

For long-lived documents that will be revised — legal agreements, technical manuals, regulatory filings — named destinations are the professional standard. Document management systems and content management platforms that generate PDF output from structured content typically use named destinations for all internal cross-references.

<a href="https://www.pdfa.org/resource/technical-note-0010/" target="_blank" rel="noopener">PDF Association Technical Note 0010</a> covers named destination best practices in detail.

Named destinations are also the mechanism behind URL-based navigation to specific PDF locations. When you link to a PDF with a URL fragment like:

`https://example.com/document.pdf#chapter-3`

…the fragment `chapter-3` is treated as a named destination by the PDF viewer. This works in: - Adobe Acrobat/Reader (both plugin and standalone) - Chrome's built-in PDF viewer - Firefox's PDF.js viewer

The <a href="https://www.ietf.org/rfc/rfc3778.txt" target="_blank" rel="noopener">IETF RFC 3778 (The application/pdf Media Type)</a> specifies that URL fragments in PDF links are interpreted as named destinations.

This makes named destinations useful for PDF content that is published on the web and needs to support deep linking — linking directly to a specific chapter, section, or figure from an external web page or another PDF. For example, a research paper's citation might link to a specific table in a PDF dataset.

To use this effectively: 1. Ensure your PDF generation tool creates named destinations for key sections 2. Use meaningful names (not page numbers, which would defeat the purpose) 3. Test the fragment URL in multiple PDF viewers to verify consistent behaviour

Named destinations are created differently depending on the authoring tool:

**Adobe InDesign** — When exporting to PDF, InDesign automatically creates named destinations for all paragraph styles marked as headings, and for anchors explicitly created with the Hyperlink > New Hyperlink Destination feature. The names match the anchor names set in the document.

**Microsoft Word** — Word's PDF export (File > Save As PDF) creates named destinations for all headings and bookmarks. Bookmarks in Word (Insert > Bookmark) become named destinations in the exported PDF.

**LaTeX** — The <a href="https://ctan.org/pkg/hyperref" target="_blank" rel="noopener">hyperref package</a> creates named destinations for all `\label{}` commands. Cross-references and table of contents entries in the PDF use these destinations. Destination names are derived from the label names.

**PDF libraries** — pdf-lib (JavaScript), pypdf (Python), and iText (Java) all support creating named destinations programmatically. pdf-lib uses `pdfDoc.catalog.set(PDFName.of('Names'), ...)` to populate the name tree.

**Acrobat Pro** — Can create destinations through the View > Show/Hide > Navigation Panes > Destinations panel. Each destination can be named and positioned by navigating to the target location first.