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 | **Version** | **Changes** | **Readiness** |
 |---|---|---|
-| 2.7.18-19 | [Dump model]<br>include validation info in relations<br>[Graph model]<br>added constants declaring vocabulary names for relation fields | beta |
-| 2.7.17 | [Dump model]<br>aligned the graph dump schema to mirror the changes in the model<br>1. Added openaccessroute at the level of the instance inside the AccessRight element;<br>2. Added pid and the alternate identifiers at the level of the instance;<br>3. Added the bipFinder measures | beta |
-| 2.7.16 | [Graph model]<br>Updated the casing of the following terms (`relation.relClass`):<br>1. `isRelatedTo -> IsRelatedTo`<br>Added the following `relClass` terms:<br>1. `IsAmongTopNSimilarDocuments`<br>2. `HasAmongTopNSimilarDocuments` | beta |
+| 2.8.20 | [Graph model]<br>added constants declaring the values used for hierarchical relationships among the organizations IsParentOf / IsChildOf | beta |
+| 2.7.18-19 | [Dump model]<br>include validation info in relations<br>[Graph model]<br>added constants declaring vocabulary names for relation fields | production |
+| 2.7.17 | [Dump model]<br>aligned the graph dump schema to mirror the changes in the model<br>1. Added openaccessroute at the level of the instance inside the AccessRight element;<br>2. Added pid and the alternate identifiers at the level of the instance;<br>3. Added the bipFinder measures | production |
+| 2.7.16 | [Graph model]<br>Updated the casing of the following terms (`relation.relClass`):<br>1. `isRelatedTo -> IsRelatedTo`<br>Added the following `relClass` terms:<br>1. `IsAmongTopNSimilarDocuments`<br>2. `HasAmongTopNSimilarDocuments` | production |
 | 2.7.15 | 1. added support for delegated authorities<br>2. fixed regex for DOI cleaning | production |
 | 2.7.14 | [Graph model]<br>Relation types are now inspired by the Datacite definitions https://schema.datacite.org/meta/kernel-4.4/doc/DataCite-MetadataKernel_v4.4.pdf <br>The changes involve the values stored in `relation.subRelType` and `relation.relClass`:<br>Updated the casing of the following terms (`relation.relClass`):<br>1. `isSupplementTo -> IsSupplementTo` / `isSupplementedBy -> IsSupplementedBy`<br>2. `isPartOf -> IsPartOf` / `hasPart -> HasPart`<br>3. `cites -> Cites` / `isCitedBy -> IsCitedBy`<br>4. `reviews -> Reviews` / `isReviewedBy -> IsReviewedBy`<br>Added the following terms [`subRelType: relClass / relClass (inverse)`]:<br>1. `relationship: References / IsReferencedBy`<br>2. `relationship: IsIdenticalTo`<br>3. `relationship: IsContinuedBy / Continues`<br>4. `relationship: IsDocumentedBy	/ Documents`<br>5. `relationship: Documents / IsDocumentedBy`<br>6. `relationship: IsCompiledBy / Compiles`<br>7. `version: IsPreviousVersionOf / IsNewVersionOf`<br>8. `version: IsSourceOf / IsDerivedFrom`<br>9. `version: IsVariantFormOf / IsOriginalFormOf`<br>10. `version: IsObsoletedBy / Obsoletes`<br>11. `version: IsVersionOf / HasVersion` | production |
 | 2.6.14 | [Scholexplorer]<br>1. Added model classes for Scholexplorer, package `eu.dnetlib.dhp.schema.sx` | production |