# GrowlDisplayProtocol.h

## Abstract

Protocols implemented by plug-ins' principal classes.

## Discussion

This header describes protocols that Growl uses to identify specific types of plug-ins. As of Growl 0.6, there are two types of plug-ins, each with its own protocol: display plug-ins, which display Growl notifications to the user; and functional plug-ins, which add features to the Growl core.

## Protocols

`GrowlDisplayPlugin`
  The display plugin protocol.
`GrowlFunctionalPlugin`
  The functional plugin protocol.
`GrowlPlugin`
  The base plug-in protocol.

© The Growl Project (Last Updated May 14, 2005)