Purpose of secret field in token

OpenVidu v2 Issues developing apps
1

What is purpose of secret field (mentioned in last line of below message taken from browser console) in the token generated by openvidu server ?

Sending request: {method:"joinRoom", params: {"token":"wss://demos.openvidu.io?sessionId=SessionA&token=tok_DyV4VFEZUzzaumLS&role=PUBLISHER&version=2.15.0&coturnIp=193.147.51.93&turnUsername=YT5UEU&turnCredential=8ar3s5&webrtcStatsInterval=30","session":"SessionA","platform":"Firefox 66.0 on Ubuntu","metadata":"{\"clientData\":\"Participant45\"}","secret":"","recorder":false}} Request: method:joinRoom params:{"token":"wss://demos.openvidu.io?sessionId=SessionA&token=tok_DyV4VFEZUzzaumLS&role=PUBLISHER&version=2.15.0&coturnIp=193.147.51.93&turnUsername=YT5UEU&turnCredential=8ar3s5&webrtcStatsInterval=30","session":"SessionA","platform":"Firefox 66.0 on Ubuntu","metadata":"{\"clientData\":\"Participant45\"}","secret":"","recorder":false}

2

This is used to manage special participants, such as the recorder participant of COMPOSED recordings. The field will be empty for normal users.