Itemtype Editing

Does anyone know how to edit Itemtype.dat
I mean software that use to edit it...
and how we could edit it...

Thanks in advance...

I can't be bothered to look for the original postings of these files, but here is a tut.

[Only registered and activated users can see links. Click Here To Register...]

Next time, use search.

Thanks, but there is some broken link over there...
I did search it but could not found
:D