Yes, similarly, I rather admire the way mysql for example has numeric error codes from a large and no-reuse-allowed table. The human readable string hints what

Yes, similarly, I rather admire the way mysql for example has numeric error codes from a large and no-reuse-allowed table. The human readable string hints what's going on; the numeric code is pretty much guaranteed to find you a relevant hit in $search_engine_of_choice, and will be relevant to your version of the software even if a similar human-readable message is used in different ways in other versions. It seems to be a pretty large up-front organizational commitment, though, and also requires significant discipline to stick to; possible in mature products, but tricky in young rapid-iteration areas.