Correction: edited out a copied phrase, my apologies.
Literal translation of the heading:
First of al Mahdis, first of the faithful; the promised al Yamani, Mr. Ahmad Hassan, guardian and messenger of Imam al Mahdi.
IOW, cleric al Hassan (al Yamani) gave himself all the above titles. Therefore, no other cleric, as in Sistani, Sadr, etc. is legit!
That's what I figured. Thanks.