Google it.
Yeah, why have any type of human interaction in a forum when you can just refer your fellow brethren to the automaton.
I’m saying this because any explanation I could offer would provide less insight than the Google results.
Less insight, perhaps, but of higher quality, which is subjective.
I personally find that googling stuff provides not much connection to the subject of study, very impersonal and try to avoid it.
For example I did google the concept, and found this https://github.com/cousteaulecommandant/ds9k.
Which is not trivial to parse, bing posited the answer as authoritative, and if you look at the code it is really nothing, it seems to be a folklore concept, and as such, it is much more aptly transmitted by speaking to a human and getting a live version than by googling an authoratitative static answer.