SAP haven't OSS note yet.
Yes both fields are optional but in the end of Anexo 24 has a structure for file where you must describe Sello, noCertificado and Certificado. In the Anexo 24 don't have information clarifying the relationship between tags Sello, noCertificado and Certificado on header of files and the file at the end of Anexo 24.
My doubt is when is described that file is how "requerido" so mandatory, well if I must send a file with Sello.... Why are these fields are optional in the header of files?
Understood what I mean?