The EXIFutils include a comprehensive documentation set containing:

Getting Started Guide An overview of EXIFutils concepts, and how to use the commands to perform common tasks Command Reference Guide A detailed description of EXIFutils command features and options Field Reference Guide A complete list of meta data fields that can be viewed/edited by the EXIFutils

These documents are also separately downloadable below.

Getting Started Guide Windows Linux/MacOS X Command Reference Guide Windows Linux/MacOS X Field Reference Guide All Platforms