Enforce Price Tolerance

 I'm hoping someone out here can help me answer a few questions about Enforce Price Tolerance in Purchasing:

1.) Does the Enforce Price Tolerance settings apply to only Indirect Requisitions or both Indirect and Direct?

2.) What happens when you have the Release Generation Method set to 'Automatic Release' and the Enforce Price Tolerance settings enabled with values?  How does the buyer find out if a tolerance has been exceeded on an autorelease document?

3.) Where does the Enforce Price Tolerance pull values from?  Just the requisition line, or does it consider the BPA at all? What about list price?