A newly issued flight instructor certificate often has the word "PENDING" in the certificate number field.
In 8900.1 Flight Standards, Volume 5, Section 1, Section 5, Paragraph 5-112(c)(2)(a) Instructions are given that the temporary airman certificate for a flight instructor should be filled in with the corresponding airman certificate number with "CFI" appended.
In the event that does not happen, and the certificate number shows "PENDING", how should the instructor format their signature to make an endorsement prior to the issuance of a permanent replacement?