Answer: superscribing

AnswerCrossword Clue
superscribingWrite or print (an inscription) at the top of or on the outside of a document
superscribingSUPERSCRIBE, to write at the top or at the head
superscribingWrite or print (a letter, word, symbol, or line of writing or printing) above an existing letter, word, or line
superscribingWrite or print an inscription at the top of or on the outside of (a document)