Apache Reference: mod_autoindex, AddIconByType

AddIconByType

Image for File Icon (by MIME Type)
Syntax: AddIconByType icon mime-type [mime-type ...]
Example: AddIconByType (IMG,/icons/image.xbm) image/*
Since: Apache 1.0

This directive is similar to AddIcon, except that a MIME content type is used for matching purposes instead of a file. The mime-type argument is a wildcard expression matching the required content type.