Current text in 8.23 and 8.23.1 is not a correct definition.  Replace with

8.23 Resource ResearchSubject - Content

A ResearchSubject is a participant or object which is the recipient of investigative activites in a research study

8.23.1 Scope and Usage
A research subject is typically a human being or an animal, but can also be a device, drug product or biological product, substance, or a tissue or other sort of sample. Research subject can also be a group or part of any of the above.

(what about environmental studies? location?)

The ResearchSubject resource describes essential information about the subject in the context of a research study. (maybe use code value pairs)

Human research subjects are traceable to a particular person but their identifying characteristics are usually hidden to protect study integrity and to protect the subject’s privacy.

Note that in a human drug trial the human is the research subject even though the drug is what is being investigated.

This is the start of revision of the Scope and Usage section - there will be further extensions to look at a series of use cases, the initial thought is:

The scope of ResearchSubject is intended to support the following use cases:
- Clinical trials (human and vetirinary)
- Pre-clinical trials
- Drug Product
- Stability studies on drug products
- Device ....
- Other bench research related to specimen
- Tissue
...