I didn't perform additional research, since i doubt i'll find something useful within short time. But if you really want to dig that deep by yourself, i'd recommend to either
1. Use Ninjastic Space search feature[1] to find post with certain keyword or from certain time range.
2. Read old documentation[2] written by user @bitrick.
3. Open Bitcoin Core repository page[3] and explore source code on older version of Bitcoin Core/Bitcoin Qt.
4. Search relevant question on Bitcoin Stack Exchange[4]. There's tag "json-rpc"[5], but remember there's no guarantee everyone use that tag when ask question about Bitcoin Core/Bitcoin Qt RPC.
[1] https://ninjastic.space/search
[2] https://bitcointalksearch.org/topic/satoshi-client-operation-overview-41718
[3] https://github.com/bitcoin/bitcoin
[4] https://bitcoin.stackexchange.com/
[5] https://bitcoin.stackexchange.com/questions/tagged/json-rpc