Customize the alert API in PI 7.31

Hi,

Currently alert API AlertRetrieveAPI and AlertRetrieveAPI_V2 is the standard API provided by SAP having fixed no. of of fields and payload but is there any way to extend this api to get more information like idoc no. or business related data for business use which can help end users also to understand the API.From which tables it extracts the data in backend ?

Thanks,

RJ