Did alot of research on these and all the inscriptions i got on the flags are correct as far as i know,free to download off the site and printed out on a A4 sheet already sized for u.
The standard inscription was the Muslim creed on the first three lines and the declaration of the Mahdi on the bottom line. They usually read:
1st line:
"Yâ allâh, Yâ Rabman, Yâ Rabîm" (O God, O Merciful One, O Compassionate One)
2nd line:
"Yâ Hayy, Yâ Qiyyûm, Ya dhil-Jilâl wal-akrâm" (O Living One, O Subsisting One, O Lord of Majesty and Honor)
3rd line:
"lâ illâh ilâ allâh Muhammad rasûl allâh" (There is no god but God. Muhammad is the Apostle of God)
4th line
"Muhammad al-Mahdi khalîfa rasûl allâh" (Muhammad al-Mahdi is the Successor of the Apostle of God)