attestation vs documentation

attestation

noun
  • A thing that serves to bear witness, confirm, or authenticate; validation, verification, documentation. 

  • The process, performed by accountants or auditors, of providing independent opinion on published financial and other business information of a business, public agency, or other organization. 

  • A confirmation or authentication. 

  • An appearance in print or otherwise recorded on a permanent medium. 

documentation

noun
  • Documentary evidence and sources. 

  • Documents that explain the operation of a particular machine or software program. 

  • Something transposed from a thought to a document; the written account of an idea. 

  • Comments that explain the usage of individual functions, libraries and blocks of code. 

  • A documentary. 

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