How copyrights are represented in CSV

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

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”?

The source_organization.csv file and the SOURCE_ORGANIZATION table in the loinc.mdb database are provided to give some basic, limited, information about some of our data sources. You have correctly pointed out that currently there is no “foreign key” identifier in the loinc.csv file or LOINC table to directly link to a record in the source_organization.csv file or SOURCE_ORGANIZATION Table in the loinc.mdb database.

After due consideration, it has been decided to add this field to the loinc.csv file and LOINC table in the loinc.mdb database in the next release currently scheduled for December of this year.

Thank you for your interest in LOINC

Great! Does that mean the “EXTERNAL_COPYRIGHT_NOTICE” column of loinc.csv will be replaced by the the foreign key, or will there be two (possibly conflicting) sources of copyright information?

As required by the LOINC terms of use, the EXTERNAL_COPYRIGHT_NOTICE field will still be included in the table. The link to the SOURCE_ORGANIZATION record will be through a new field named LOINC.EXTERNAL_COPYRIGHT_LINK. This field will be a foreign key reference to the SOURCE_ORGANIZATION.COPYRIGHT_ID field.

We realize that this does result in some duplication, but having the LOINC.EXTERNAL_COPYRIGHT_NOTICE field in the table is required. You should also be aware that the value of the LOINC. EXTERNAL_COPYRIGHT_NOTICE field is generated and maintained by an internal process and will not necessarily match the value of the SOURCE_ORGANIZATION. COPYRIGHT field. You can find information about using the LOINC.EXTERNAL_COPYRIGHT_NOTICE field in the LOINC terms of use at

Thank you. You’ve clarified this a lot, and I’m still a bit confused about what to do when both LOINC.EXTERNAL_COPYRIGHT_NOTICE and LOINC.EXTERNAL_COPYRIGHT_LINK are populated.

It sounds like EXTERNAL_COPYRIGHT_NOTICE is the only legally binding copyright information, and EXTERNAL_COPYRIGHT_LINK provides potentially useful additional information that should be ignored in the event of a conflict. Is that correct?

The LOINC “Terms of Use” is the official legal document that explains where and when you need to include the copyright information. As far as legal documents go, it is fairly easy to read and user friendly. It contains several explicit mentions of where and when you need to use the EXTERNAL_COPYRIGHT_NOTICE field. You can find the terms of use at

Yes, as near as I can tell from the current terms of use, the EXTERNAL_COPYRIGHT_LINK (indeed, the entire SOURCE_ORGANIZATION table) can be ignored entirely. Perhaps some day the terms of use will be updated to explain when the EXTERNAL_COPYRIGHT_LINK is meaningful. In the mean time, I’ll disregard the SOURCE_ORGANIZATION table and any references to it. Thank you for your help.