bookshelf vs rubric

bookshelf

noun
  • A shelf or shelves for storing books for easy visual reference. 

rubric

noun
  • A heading in a book highlighted in red. 

  • A flourish after a signature. 

  • Red ochre. 

  • A set of scoring criteria for evaluating student work and for giving feedback. 

  • The directions for a religious service, formerly printed in red letters. 

  • A title of a category or a class. 

  • An established rule or custom; a guideline. 

verb
  • To adorn with red; to redden. 

  • To organise or classify into rubrics 

adj
  • Coloured or marked with red; placed in rubrics. 

  • Of or relating to the rubric or rubrics; rubrical. 

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