CSV structure for copyrights

The User’s Guide is unclear about how LOINC represents copyright information. I do not see my question answered in the FAQ, or searching this forum.

There is a table of copyright information in source_organization.csv.

I expected one of the columns of loinc.csv to reference the the “COPYRIGHT_ID” column of source_organization.csv. Indeed the description of this column (in Table 28c on page 93 of the “LOINC Users’ Guide”) specifies that the “COPYRIGHT_ID” column is referenced by a foreign key in the LOINC table… but it does not say which column in loinc.csv contains that foreign key.

The only column in loinc.csv that (based on the name) could be a foreign key pointing to a row in source_organization.csv is “EXTERNAL_COPYRIGHT_NOTICE”. However, looking at loinc.csv, “EXTERNAL_COPYRIGHT_NOTICE” actually contains a full, lengthy, copyright statement, not values from any source_organization.csv “COPYRIGHT_ID” column.

Is source_organization.csv actually unused? Or am I just overlooking some foreign key other than “EXTERNAL_COPYRIGHT_NOTICE”?