Error codes and status codes

A set of error codes is defined for each PKIFv2 subsystem (e.g. path processing, cryptography, etc.). Each error code is described in a table at the beginning of the reference book for each subsystem. For all except the most common errors, a list functions and class methods that originate each error code is provided. 

The values may be used to convey information indicating the cause of a failure associated with an exception object or used to convey information to support a decision rendered by the library, e.g. path validation failure. Error codes are frequently accompanied by a text string that provides additional runtime information about the cause of a failure that resulted in an exception.