I petitioned I-130 for my parents in February 2018. Recently, my dad alone got a 'Request for Evidence' .
RFE says
"Submit original document
Submit the original birth certificate the copy not clear to read. Do not submit a photocopy of the document. the original document will be returned to you.
Submit birth certificate
Submit a photocopy of the original birth certificate of
User's Location: Santa Clara, California, United States of America
Category: Family-based Green Card