File3

File3 is a hypothetical file format used in computing education and documentation to illustrate how structured data can be stored and exchanged between programs. It is commonly presented in textbooks and tutorials as a simple alternative to more feature-rich formats.

The text-based version of File3 emphasizes readability. It typically uses a header with a short magic token (for example, "F3") and a version number, followed by a sequence of records. Each record is defined as a set of fields written as key:value pairs, with support for comments introduced by #. Fields may be grouped into sections using a lightweight indentation or braces in some variants. A minimal parser can validate the header, then iterate over records, converting values to basic types such as strings, numbers, and booleans.

A binary variant of File3 has been described in educational materials to demonstrate compact serialization. In practice, File3 is not widely standardized, and any concrete implementation tends to pick its own conventions for endianness, field tags, and validation.

Usage and reception: Because of its simplicity, File3 is popular in teaching exercises, code samples, and small configuration tasks. It is generally considered a didactic format rather than a production standard, with JSON, YAML, TOML, or INI serving as more common real-world choices.

See also: JSON, YAML, TOML, INI, XML.