I found other answers on this, but none of them seemed to answer what I am looking for. This might be a duplicate, I don't know.

I wanted a list of sub-domains of Stack Exchange that are not mentioned over here https://stackexchange.com/sites

Some of the sub-domains I found which were not mentioned are

https://chat.stackexchange.com

https://data.stackexchange.com

Are there any other which are not mentioned ?