Hello, team!

Zabbix 3.0, 3.2, 3.4 and 4.0 have following information on manual/api/reference/host/object page regarding tls_accept:

Connections from host.

Possible bitmap values are:
1 - (default) No encryption;
2 - PSK;
4 - certificate. 

In reality it's a mask, and it could also have values of 3, 5, 6, 7 - it's how it works but now how it's documented at the moment.