User:Peter F. Patel-Schneider/metaclass table

Here is some information about the top level of the Wikidata ontology, as of 10 August 2023, along with some comments about their instances and subclasses and what I think should be done with them. As well, I think that the top level classes should have good Wikidata usage instructions that describe better what the classes are for. I have put Wikidata usage instructions on fourth-order class (Q24027474) and fifth-order class (Q24027515) as examples.

Summary of the top-level ontology classes with some commments (<- is number of instances, <= subclasses)
entity <- <= instance of subclass of comments
first-order class (Q104086571) 44 0 second-order class (Q24017414) fixed-order class (Q23959932) all instances look OK, no interwiki links
second-order class (Q24017414) 423 4 third-order class (Q24017465) fixed-order class (Q23959932), metaclass (Q19478619) many instances questionable, no interwiki links
third-order class (Q24017465) 22 0 fourth-order class (Q24027474) fixed-order class (Q23959932), metaclass (Q19478619) many instances questionable, no interwiki links
fourth-order class (Q24027474) 1 0 fifth-order class (Q24027515) fixed-order class (Q23959932), metaclass (Q19478619) unused, no interwiki links
fifth-order class (Q24027515) 1 0 fixed order class of higher order (Q24027526) fixed-order class (Q23959932), metaclass (Q19478619) unused, no interwiki links
fixed order class of higher order (Q24027526) 1 0 variable-order class (Q23958852) fixed-order class (Q23959932), metaclass (Q19478619) unused, no interwiki links
fixed-order class (Q23959932) 0 6 variable-order class (Q23958852) class (Q23960977) unused, no interwiki links
variable-order class (Q23958852) 15 0 variable-order class (Q23958852) class (Q23960977) many instances questionable, no interwiki links
metaclass (Q19478619) 80 23 variable-order class (Q23958852), concept (Q151885) class (Q23960977) linked to wikipedia pages for metaclass in the semantic web, some instances questionable, many subclasses questionable, move most instances and subclasses to one of the fixed-order classes
metaclass (Q19361238) 476 9 metaclass (Q19478619), class (Q21522864) no interwiki links, many instances questionable, many subclasses questionable, merge with second-order class?
entity (Q35120) 21 45 variable-order class (Q23958852) class of all entities, linked to many wikipedia pages
other high-level classes
class (Q5127848) 3 8 metaclass (Q19478619) abstract entity (Q7184903) linked to wikipedia pages for class in logic and philosophy, move incoming links to class (Q16889133)
class (Q16889133) 253 237 metaclass (Q19478619), variable-order class (Q23958852) linked to English wikipedia page for class in knowledge representation, most instances are first-order classes, many subclasses questionable
abstract entity (Q7184903) 17 63 variable-order class (Q23958852) object (Q488383)
object (Q488383) 708 88 variable-order class (Q23958852) entity (Q35120)
Q104093226 1 0 class (Q16889133) delete?
concept (Q151885) 2668 91 variable-order class (Q23958852) abstract entity (Q7184903)