foreslash vs shilling mark

foreslash

noun
  • Synonym of slash ⟨/⟩. 

shilling mark

noun
  • Synonym of slash ⟨/⟩ in its use to mark the amount of shillings in a sum or (obsolete) in all its uses. 

How often have the words foreslash and shilling mark occurred in a corpus of books? (source: Google Ngram Viewer )