If I submit DOCX documents only, what is rendered by the EPO for the examiner and what is rendered for the Register?

Once filed in DOCX format, the EPO will convert the application documents into ST.36 XML for further processing. If there are any errors, inconsistencies or omissions, the original disclosure in DOCX format will be consulted. If any doubts or inconsistencies remain despite having consulted the DOCX file, the PDF back-up copy, if filed, can be checked. It is important to note, however, that a PDF back-up copy can never be used to replace the DOCX version. Both the application documents in DOCX format and the PDF back-up copy will be made available for file inspection in accordance with Article 128 EPC.