ESRI Symbol Sets

[JimKniss]

ESRI has many different symbol sets that come with the basic software. My question is where did these come from? As an example, there is a Petroleum set that has many unique lines, fills and marker symbols. Did ESRI develop these or are they standards that are accepted by the various industries identified.

Thanks

[JimBarry]

I'm going to move this to the Cartography forum to see if we can get some discussion going there.