As of now, the first link in https://github.com/SAP/styleguides/blob/main/clean-abap/CleanABAP.md#if-your-global-class-is-create-private-leave-the-constructor-public - "However, according to the article Instance Constructor of the ABAP Help," ends up in a 404-Error / "Sorry We couldn't find that page." This is the link: https://help.sap.com/doc/abapdocu_latest_index_htm/latest/en-US/abeninstance_constructor_guidl.htm