certifying

/S ER1 T AH0 F AY0 IH0 NG/
verb
  1. 1

    To attest to (a fact) as the truth.

  2. 2

    To authenticate or verify in writing.

  3. 3

    To attest that a product, service, organization, or person has met an official standard.

    โ€œThese blankets have been certified as fireproof.โ€

  4. 4

    To inform; to tell (a person) that something is true.

  5. 5

    To assure (oneself) of something; to ascertain.

Source: https://en.wiktionary.org/wiki/certify, https://en.wiktionary.org/wiki/certifying