For the API that Washington State had BioTrackTHC build they have not provided any documentation on the error codes provided by this API.
Most API Providers (read: all others) provide some type of documentation on what kind of error codes could be emitted by their software.
For over six months the existing documentation has shown:
This document does not currently have a detailed list of error codes. That will be forthcoming in the final draft for ease of debugging effort
After months and months of waiting we've created some of our own documentation for this as yet unknown data.
One thing you will notice is how the same few error codes are re-used over and over. And also how some error codes have different meanings.
For example, many of the API calls return an error code of 602 or 1000. And each of those codes has many different errors they could describe.
What professionals do is to create unique error codes for all conditions. For example, take at look at this excellent documentation by Twilio
We hope the next providers to work on Marijuana Traceability will be more professional than the system built by BioTrackTHC for the State of Washington.