-% total mf for class specific items. help?

I was playing some ladder D2 Expansion and I told this guy in game that I was using Occy. He said, don't you know that class specific items give 1/3 less total mf. I said no I didn't know that (strange after all the years of playing D2 too). He said go onto Arreat Summit and go to the Expansion section.
I've went to Arreat Summit but can't seem to find it. Can someone please verify whether this is true and/or list the link for reference?
Thanks.|||You got trolled. This claim to complete BS.