Nice, except starting off with an example using the RETURN to return the answer - something I've seen too many programmers use because they don't understand its reason for existence

Maybe you can add a paragraph on what it is (INT only), why it exists (return error / success information, similar to C - not VB where you can return any data type) and how to catch it in ADO (and maybe what to do with it!)?

And maybe link to some nice articles about error handling (why and best practice - or worst 🙂 )...