The Document Structuring Convention is a set of comments placed in a page-description file so that another program can tell where each page starts, which fonts are needed, and how the pages are ordered. The comments do not draw anything. They describe the file to the program that will print or embed it.
The convention is used inside Encapsulated PostScript (EPS) and in ordinary page-description files of the same family. A preview image may sit beside the description. The structuring comments are what let a second program pick out a single page without executing the whole file.
What the Comments Mark
- Pages. Where one page ends and the next begins.
- Resources. Fonts and other pieces the page needs.
- Bounding. The rectangle the drawing occupies, so it can be placed on another page.
Structuring Comments and the Drawing
| Compared | The Comments | The Drawing Commands |
| Purpose | Describe the file | Mark the page |
| Visible output | None | The printed image |
| A program that only needs the size | Reads the comments | Does not have to run the drawing |