Background
This was spawned by JIRA issue: 
FLT-52 - Use of SKOS Concepts in FIBO IN PROGRESS
There are two separate but related issues:
- How and when should skos:Concept be used in FIBO?
- How to represent concepts that are used to classify things, when you do not want to use owl:Class, and what criteria can be used to decide which approach to use.
This started when I thought one way to answer the first part of question 2 is to use skos:Concept. It was decided to not do that, instead, to use existing FIBO terms.
Below I summarize the discussion on the first issue.
Here is a discussion on the second issue above: When to use Classes vs. Classifiers.
Summary: skos:Concept
It was decided that we will not use skos:Concept for FIBO. Instead we will either create classes directly in owl, or we will us the existing FIBO classification vocabulary:
- fibo-fnd-arr-cls:Classifier
- fibo-fnd-rel:isClassifiedBy