[Koha-devel] 942 versus 952

Hi all I am wanting to clarify the usage of the 942$c field versus the 952$y field as I am setting up a new bib framework. I am wondering if it is necessary to have both the 942$c field and the 952$y field in the framework as they seem to record the same information i.e Koha item type. Is there an advantage to recording the same information in both fields and if not which is the preferred? We are using Koha 3.22 thanks! Karen