Autographed Alum. Weldment

[BlackZR1]

Was doing so some undercar detailing and removed the spare tire hardware. Noticed that the aluminum weldment behind the rear fascia had someone's initials and date. Based on position, would have been applied before assembly. 6/1990 is about right for my car. Was this customary? Anyone know BJ lol?
I have to admit that piece is a work of art!
Attached pics are with camera at diff facing rear of car, gas tank above.

Roger