Item category change of BOM header material after BOM transfer

Hi.

I heard that the item category of BOM header material would change into 'T(text item - for information only) ' after BOM transfer in PS.

I tested it on my company's IDES. However, it didn't happen. The item category of a header material was 'L' after BOM transfer as well as before.

There extists customizing to change item category ?

Thanks for your help !