Apache Reference: mod_actions

mod_actions - Content Selection by Content Types and Request Methods
Since Apache 1.1, src/modules/standard/mod_actions.c
Alexei Kosut (1996)

mod_actions provides a way to trigger a CGI script when a specific MIME content type of a document is encountered or when the request uses a specific HTTP method. This module can be used to create dynamic content when specific documents are requested or to implement special extensional HTTP methods (such as PUT) via CGI scripts.

Directives:

Action    Script