Authorization control for Material Memo in MD04

Dear Experts,

We want to maintain some plant specific text information against a Material Master.

We have identified “Material Memo” in MRP 4 view to maintain the plant specific text.

The Material Memo is visible in MD04 screen, where user can change / remove the text maintained in material memo.

Our Query are –

1. Is there any better solution to maintain Plant Specific Text?
2. Can we control user wise authorization in MD04 so that end user will not be able to change the material memo through MD04.

Thanks in advance,

Regards,

Srinathan.