ont: Copies *Includes explanation to OTRL.ttl

OTRL.ttl

@@ -20,6 +20,22 @@
 # can be issued at its source location:
 # <https://github.com/OPEN-NEXT/OKH-LOSH/master/OTRL.ttl>
 
+# NOTE:
+# Regarding the use of `schema:domainIncludes`
+# and `schema:rangeIncludes` in this ontology:
+# Looking at the definitions for the RDFS version
+# of the two, `rdfs:domain` and `rdfs:range`:
+# * https://www.w3.org/TR/rdf-schema/#ch_domain
+# * https://www.w3.org/TR/rdf-schema/#ch_range
+# and as described in this StackOverflow answer:
+# <https://stackoverflow.com/a/74782257/586229>,
+# multiple objects for the two RDFS properties mean,
+# that *all of them* apply, simultaneously,
+# not *one of them*.
+# You may think of this as an `AND` coupling.
+# We want the *one of them* meaning though (`OR`).
+# The `schema:*` properties give us just that.
+
 <>
   a owl:Ontology ;
   vann:preferredNamespacePrefix "otrl" ;