the act of acknowledging

act of recognizing authority or truth of something

the act of confirming or being confirmed (all senses)

ratification, validation, proof

anything that gives a reason for believing, that makes clear or proves, something

proof

(an example of) evidence that is sufficient to show that something is a fact

evidence, authentication

a set of questions, tasks etc used to measure a person's knowledge or ability; an examination or trial (of something) to find its quality, value, composition etc

examination, quiz

a formal statement especially in a law court, that something is true

declaration about truth; proof