bookmark vs marker pen

bookmark

noun
  • A strip of material used to mark a place in a book. 

  • A record of the address of a file or Internet page, serving as a shortcut to it. 

  • A pointer found in a nonclustered index to a row in a clustered index or a table heap 

verb
  • To create a bookmark. 

marker pen

noun
  • A pen, often with a thick tip made of felt. 

How often have the words bookmark and marker pen occurred in a corpus of books? (source: Google Ngram Viewer )