Solution : https://service.sap.com/sap/support/notes/370308 (SAP Service marketplace login required)
Key words :
additional key words product availability check, create data element /sapapo/cortyp, component type /sapapo/cortyp, apo availability check, add component type, add component cortyp, domain /sapapo/cortyp, choose /sapapo/atp, attached source code, structure /sapapo/atpcorr
Related Notes :
374206 | Assigning order numbers a new key is not possible |