First create a new project with the use of the Doctype Add-on Archetype. The interface to use the archetype is simplified by the create mojo. So we recommend to use the following command on the commandline. This reduces the number of parameters you have to specify to one (shortId), also it is recommended to also provide a name for the new project (projectName).

mvn doctype:create -DshortId=myshortid -DprojectName="My Doctype Add-on"

Specify a short ID (only characters, digits allowed except as first char) and an optional project name (which is recommended). With that a project based on Maven for the add-on for the PDAC1 is created.