General
Configuration
Implementation
${project.reporting.outputDirectory}/../apidocs
You may want to consider the implementation of PackageSortedSinkReportGenerator and CodeSortedSinkReportGenerator as examples.
The register your report in the maven-exceptioncodes-plugin configuration like this:
Please refere to Using the Report and Plugin documentation (especially Mojo exceptioncodes:exception-codes-report) for further information about configuration of the plugin.