Links between General Finnish Ontology YSO and Wikidata have been added and maintained since 2019 by YSO maintenance. First set of YSO concepts, ca. 7300 concepts (of ca. 30000 in total), was processed in 2019-2020 with links to matching Wikidata items added when available. Linking was carried out by going through a list of YSO concepts with link suggestions to Wikidata. The suggestions were either approved or disapproved by YSO maintenance. The list of suggestions were was generated automatically by using the following three sources:
1) List of Library of Congress Subject Headings with links to both YSO concepts and Wikidata items.
2) List of subject headings used by Finnish Broadcasting Company Yle with links to both YSO concepts and Wikidata items.
3) List of the most often used YSO concepts in indexing, according to metadata from Finnish search service Finna metada, with label matches from Wikidata.
- Linking is done by using the SKOS property skos:closeMatch.
- Linking is done by finding the semantically most accurate match in Wikidata for the YSO concept.
- When no suitable match is found, no link is added.
- One YSO concept can be linked to several Wikidata items, when YSO concept's meaning covers these items.
- Several YSO concepts can be linked to the same Wikidata item, when the item's meaning covers these YSO concepts.
- No links are added between YSO concepts and Wikidata items linked to a Wikipedia disambiguation page.
- Guidelines for linking YSO concepts to Library of Congress Subject Headings (in Finnish) are followed when suitable.
- Wikidata items and Wikipedia articles can be edited when there is a direct benefit for linking YSO concepts to Wikidata (ie. through editing the Wikidata item becomes more accurate making it possible to add a link between a YSO concept and the item). General Wikidata guidelines are followed in this. Editing concerns correcting straightforward errors and inaccuracies with a goal of improving the item's quality and semantic unity. Editing is only done to Finnish, Swedish or English concent. Editing covers content and is limited to the following:
- Editing, adding or removing a Wikidata label, definition or alias.
- Adding, removing or changing a link to a Wikipedia article.
- Merging two Wikidata items by using Wikidata's merge function.
- Changing the headline of a Wikipedia article linked to a Wikidata item.