[Koha] Koha Item Type 942$c, 952$y

Dear All, I am migrating my data from oracle database to KOHA. I would like to use the 942$c to store document types such as handbooks, dictionary etc (I will not create any circulation rules for these values) and 952$y for koha item type used for circulation rules. I intend to edit the MARC framework and update the authorized value of 942$c to a new created authorized value such as DTYPE. However KOHA links this field to biblioitems.itemtype. I wanted to understand how and where is this field used in KOHA functions. Will this cause any malfunctioning with respect to lending or any other functions. With best regards, Naveen Ali ITM-JE (EAKL) Inst Representative for HEC Digital Library Resources. NEDUET, Karachi.