If you need to create custom error codes for sending mails to stakeholder etc this is where you would create them, they can be used in the processing of a document where you fail a document with your own error code.
Error codes below 100000 is system specifics and can not be edited or deleted, everything above that will be manageable through the UI.
To Create a new Error code, go to Developer/Error codes:
Here you can see the error codes already existing:
and to create a new Click the + left to the seach bar:
then a new window will appear where you can type the information to a new error code:
The number of the code must be shared with the developer who is to raise the error code.
You can raise a custom error code from a mapping, schematron validation or a custom component.