Hi colleagues, Converting to the MARC21 structure so far has been a near impossible task for our library. MARC seems to be so confusing, and I was wondering if there are any MARC experts out here willing to provide me with some answers. 1. In our old cataloguing structure, when we catalogued encyclopedias, for example, we would classify them as COLLECTIVE. These were the fields used: 021: Volume Number 023: Personal Author 024: Corporate Author 025: Title 027: Total Number of Volumes I have visited many libraries' websites using Koha, and have noticed some differing fields being used for encyclopedias. Does the title of an encyclopedia go under the normal 245 field, and so on? I also noticed some libraries using field 300, subfield a (Extent), to record how many volumes are in that particular set, while other libraries used the field 520, subfield a (SUMMARY) to record their volume amount. 2. What fields do periodicals use in Koha when you catalogue them? In our old format, we classified them as SERIALS, with different fields as well. 3. Are the control fields needed when I catalogue a book? We will eventually receive training for MARC, but that won't be until next year or so. Here's hoping that someone provides me with some answers. Thanks.