codify vs preorder

codify

verb
  • To collect and arrange in a systematic form. 

  • To reduce to a code, to arrange into a code. 

preorder

verb
  • To sort or arrange beforehand. 

  • To order (goods or services) in advance, before they are available. 

adj
  • Such that, recursively, the root is visited before the left and right subtrees. 

noun
  • A binary relation that is reflexive and transitive. 

  • An order for goods or services placed in advance. 

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