.DIZ File Format

Introduction

A FILE_ID.DIZ file is a short description of a program, placed inside its archive so that the description travels with the download. It comes from the era of bulletin board systems in the early 1990s. When someone uploaded an archive, the board’s software could unpack this one file and use it as the listing, so that nobody had to type a description by hand. DIZ stands for “description in zip”.

Clark Development, maker of the PCBoard bulletin board software, and the Association of Shareware Professionals backed the idea, and it became the normal way to describe shareware. The extension is almost always found on a file with exactly this name.

Structure

The file is plain text at the top level of an archive. The published specification allows at most ten lines of 45 characters, in 7-bit ASCII. Practice was looser: many later files keep to about 45 columns but use the extended characters of code page 437, the IBM PC character set, for lines and block graphics, or add NFO-style art. A board operator’s software might add its own lines as well, such as an advertisement for the board.

The text is usually the name and version of the program, a sentence or two about it, the distribution status, and for files split across disks a part number such as [1/4]. Lines are ended with carriage return and line feed. A separate DOS convention, the DESCRIPT.ION file used by 4DOS, is unrelated.

Example Utility v2.1 [1/2]
A small tool that renames groups of
files by pattern, with undo.
Shareware. Registration $10.
Example Software, 1994.

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