External communication of sustainability efforts is voluntary. In order to enable comparison between companies but also to document internal progress over time GRI is often applied. Based on a standard questioner, the global reporting initiative promotes a systematic reporting scheme.
Companies active in sustainability or about to set up sustainability measures can profit from looking at the GRI guidelines in order to use this recognised form of external and internal communication as inexpensive additional benefit from already existing sustainability efforts.
Heinz Schmid helps you with your GRI sustainability reporting.