ontology prefixes and metadata

[VladimirAlexiev]

I did a review of bibliotek-o.owl:

• don't use empty prefix for ontology terms, some repos are promiscuous and will add it as a namespace, and empty prefix is bad pracice
• register http://bibliotek-o.org/ontology/ at prefix.cc
  Hint: http://prefix.cc/bo is not yet taken, whereas bib: is taken
• if you emit vann:preferredNamespacePrefix, you must also emit vann:preferredNamespaceUri
• define and use a prefix bf: http://id.loc.gov/ontologies/bibframe/
  Note: prefix.cc says that http://bibframe.org/vocab/ is a more popular namespace for bf:
• define and use a prefix for http://www.w3.org/ns/oa#
• add rdfs:isDefinedBy to every ontology term
• IMHO emit the ontology metadata against the versioned namespace http://bibliotek-o.org/1.1/ontology/.
• don't fake-complete dct:issued, dct:modified to seconds eg 2017-04-22T00:00:00-04:00 (you did not really do this at midnight, right)?
• Use dates with proper datatype, eg "2017-04-22"^^xsd:date
• replace prose eg
  skos:scopeNote "This class is derived from the MARC relator: http://id.loc.gov/vocabulary/relators/abr."@en .
  with a link:
  rdfs:seeAlso <http://id.loc.gov/vocabulary/relators/abr>.
  (or dct:source)
• why define :hasSource rather than use dct:source? same for :isSourceOf