rule vs watermark

rule

verb
  • To mark (paper or the like) with rules (lines). 

  • To establish or settle by, or as by, a rule; to fix by universal or general consent, or by common practice. 

  • To regulate, be in charge of, make decisions for, reign over. 

  • To decide judicially. 

  • To excel. 

noun
  • A determinate method prescribed for performing any operation and producing a certain result. 

  • A regulating principle. 

  • A ruler; device for measuring, a straightedge, a measure. 

  • A normal condition or state of affairs. 

  • A regulation, law, guideline. 

  • An order regulating the practice of the courts, or an order made between parties to an action or a suit. 

  • A straight line (continuous mark, as made by a pen or the like), especially one lying across a paper as a guide for writing. 

  • The act of ruling; administration of law; government; empire; authority; control. 

watermark

verb
  • To mark paper with a watermark. 

  • To mark a datafile with a digital watermark. 

noun
  • A mark indicating the level to which water has risen. 

  • A translucent design impressed on the surface of paper and visible when the paper is held to the light. 

  • A logo superimposed on a digital image, a television broadcast, etc. 

  • A value stored in a datafile to ensure its integrity, so that if the file's contents are changed then the watermark will no longer match the contents. 

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