Model Board Symbology Questions

[NW Mailing List]

A much more general question for the truly uninformed on this topic:  is there a reference document that has a list of all these symbols used on both track charts and interlocking model boards?
Question Two:  Are these symbols "standardized"  for the industry, or by machine manufacturer, or just by individual railroad. 

There are many interesting articles about major towers/ interlockings.  They all include track charts, but none has a legend on it.  These same articles often include photos of the model boards. 

Any help in identifying a reference will be appreciated.  My limited internet search skills have left me empty handed. 

Jim Stapleton
Soggy, cold, NoVA