Market Data Definition Language (MDDL)
Google
The Financial Information Services Division of the Software & Information Industry Association
MDDL 2.5-beta : rating
MDDL 2.5-betaSchema DocumentationNo Graphics?
Index: MDDL 2.5-beta Schema Documentation
Element: rating
Description: A quality or subjective indication of the value or stability of the rated entity.
Used by: agencyRatings 
Attributes:  
Uses: sequence  code  name  previousCode  period  ratingType 
Classification: Container "property"
Diagram: