I answered your question: "So are those used in any infinity game?"
And my point was, somewhen at the early development of bg1, someone wrote those field names, but didn't follow up with any implementation. The rest of the games in the following 20 years just inherited the names. As of the EE, you can expect unused fields to be re-purposed when needed.
The post of mine you're quoting has nothing to do with the answer you gave me, and to clear things up, the struct names are meaningless, I only included them for interest so I really have no idea what you're talking about.
I accepted your answer, and replied as to why I was doing this, which has nothing at all to do with this answer.