Some of the examples are taken from: Marc21 Concise format for bibliographic data For classifying music please refer to: classification and shelving of multi-media items. (R) = a repeatable field. (NR) = a non-repeatable field. Leader: j = musical sound recording This section offers quite a lot of choice. If you want to provide a very detailed 007 tag click here for more information. 008 (Anything mentioned in 008 needs to be mentioned in body of record too.) NAM a= language material, t = manuscript language material. 245 Main title (NR) Indicator 1: 0 = no 100 field 1 = 100 field present