ERC certificates are automaticaly generated by CoSy when the Course Director confirms all the participants who passed the course.  CoSy loads the CD signature from his or her CoSy profile.  

If the signature of the Course Director isn't present on the certificate, this means that the Course Director still needs to upload a signature. Once the signature has been uploaded, it will appear automatically on certificates of courses he or she has organised.

He or she can also sign by hand when the certificates are awarded in person.