Basic Formal Ontology

1. https://github.com/bfo-ontology/BFO/wiki
2. http://basic-formal-ontology.org/

BFO 2020

1. http://purl.obolibrary.org/obo/BFO_0000001 entity
   1. http://purl.obolibrary.org/obo/BFO_0000002 continuant
      1. http://purl.obolibrary.org/obo/BFO_0000004 independent continuant
         1. http://purl.obolibrary.org/obo/BFO_0000040 material entity
         2. http://purl.obolibrary.org/obo/BFO_0000141 immaterial entity
            1. http://purl.obolibrary.org/obo/BFO_0000006 spatial region
            2. http://purl.obolibrary.org/obo/BFO_0000029 site
            3. http://purl.obolibrary.org/obo/BFO_0000140 continuant fiat boundary
      2. http://purl.obolibrary.org/obo/BFO_0000020 specifically dependent continuant
      3. http://purl.obolibrary.org/obo/BFO_0000031 generically dependent continuant
   2. http://purl.obolibrary.org/obo/BFO_0000003 occurent
      1. http://purl.obolibrary.org/obo/BFO_0000008 temporal region
         1. http://purl.obolibrary.org/obo/BFO_0000038 one-dimensional temporal region
         2. http://purl.obolibrary.org/obo/BFO_0000148 zero-dimensional temporal region
      2. http://purl.obolibrary.org/obo/BFO_0000011 spatiotemporal region
      3. http://purl.obolibrary.org/obo/BFO_0000015 process
      4. http://purl.obolibrary.org/obo/BFO_0000035 process boundary

Release

https://ncorwiki.buffalo.edu/index.php/BFO_Release_History:_From_BFO_1_to_BFO-ISO

1. 2001 : BFO 1
2. 2007 : BFO 1.1
3. 2015 : BFO 2
   1. http://ncorwiki.buffalo.edu/index.php/Basic_Formal_Ontology_2.0
   2. http://ontology.buffalo.edu/bfo/BFO2.png
4. 2020 : BFO-2020

Third party text

BFO based ontology

1. https://www.sciencedirect.com/science/article/pii/S1877050919307380 - The Ontology of Systems Engineering: Towards a Computational Digital Engineering Semantic Framework

Fiat - Bona Fide

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3520998/ - Fiat or Bona Fide Boundary—A Matter of Granular Perspective