Generally speaking I don't like Hungarian notation, but I find it is actually kind of helpful in JDE in a couple of situations so I still use it for the most part. Also I use it to be consistent with pristine code.
As far as appending the DD Alias to the variable/structure name, I am really not a big fan of that either and I usually don't do it, unless the Alias is just as recognizable as the "long name". In other words if I just need a number and I use GNUM2 I find it ridiculous to name my variable mnAmountGNUM2. However, I will occasionally use it if I think it makes the code more readable and self documenting as in mnShipToSHAN. But even then, I tend to lean towards not appending the DD Alias... I mean you can easily find out the DD item for vars/struct members with relative ease.
As others have said, it comes down to any coding guidelines/precedents that your organization has and personal preference. There really isn't a right or wrong answer.