1. Publisher
   1. ONIX
   2. CISS Webform
   3. CIP Web form
   4. Legal Deposit Form
   5. New Books Web form
2. Creator
   1. Thesis Web Portal
   2. Header of electronic document
   3. LAC Web Form
3. Item itself
   1. Digital audio: ID3 tags, BWF
   2. Video: MPEG 7
   3. EPub: Dublin core in Doc Header
4. Data Aggregators
   1. Biblioshare ONIX
   2. DMDS XML format digital audio
   3. OCLC: MaRc21
   4. Open Source: MusicBrainz, MaRc Thing
   5. Proprietary: TuneCore, GraceNote
5. Other Libraries
   1. Union Catalogue
   2. BanQ
   3. Library of Congress
6. User Contributed
   1. keyword tags
7. LAC Created
   1. Name Authorities
   2. Name/Titles
   3. Data LInking/ Relationships
   4. Subtopic 4