rubber stamp vs validation

rubber stamp

noun
  • A person or organisation that approves, routinely or as a formality, matters decided by some other person or organisation. 

  • A piece of rubber or similar material with a design or text carved or molded for the purpose of transferring ink or dye to imprint that design on another object. 

adj
  • Of a person, organisation, or process, making decisions or approving matters routinely or without real power. 

verb
  • To process, approve or decide matters routinely rather than through careful consideration. 

validation

noun
  • The act of validating something. 

  • Something, such as a certificate, that validates something; attestation, authentication, confirmation, proof or verification. 

  • The process of identifying a new prisoner's gang affiliation. 

  • The process whereby others confirm the validity of one's emotions. 

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