solreffriction, solimpfriction，solreflimit, solimplimit parameter meaning

[lcyawym]

My setup

latest

My question

I have searched through the official documents and codes, but I have not found any place that explains these parameters. Where can I find the meaning and usage of these parameters?
I saw the usage of sorel and solimp in the official documents, but I did not find these parameters. Thank you

Confirmations

• I searched the latest documentation thoroughly before posting.
• I searched previous Issues and Discussions, I am certain this has not been raised before.

[yuvaltassa]

"Contact reference acceleration, in the friction dimensions."

For limit the semantic is exactly the same as with contacts