Target audience: Practitioners interested in programming language design and familiar with representations of errors in at least a few different languages such as error codes, checked/unchecked exceptions, tagged unions, polymorphic variants etc.
Estimated reading time: 60 to 90 mins.
Quoting the conclusion:
The linked The Error Model article is very exhaustive and good.
They end with more concrete experience/findings/conclusions - given the context of a more concrete project and scope and goals.