[Koha] I haven't 952 field

Dear all, I have the problem that I can't get the link place hold in my opac.Looking the guide of koha, I noticed the utility of 952 field in cataloguing,i think that is the origin of my problem,because I'haven't the 952 field in cataloguing when i add a new item,and in my opac i haven't the status of my item. 1- How i can add the 952 field in my default marc 21 framework? 2- The function Place on reserve is the same of Place hold? Will be the end of my problems whit Koha?