Utah Code § 57-2-15
No certificate of any such proof shall be made unless a competent and credible witness shall state on oath or affirmation that the competent and credible witness personally knew the person whose name is subscribed thereto as a party, well knows the subscribing party's signature, stating the competent and credible witness's means of knowledge, and believes the name of the party subscribed thereto as a party was subscribed by such person; nor unless a competent and credible witness shall in like manner state that the competent and credible witness personally knew the person whose name is subscribed to such conveyance as a witness, well knows the subscribing witness's signature, stating the competent and credible witness's means of knowledge, and believes the name subscribed thereto as a witness was thereto subscribed by such person.
Utah Code § 57-2-15