The WA_TRUST stanza is used to control which WorkGroup Servers can connect to a given agent. This can be used to prevent the PROD WGS from connecting to a TEST agent for example.
The syntax is
WA_TRUST::<USERNAME>::<IPADDR>::<APPLNAME>={1|0}
E.g.:
WA_TRUST::*::192.168.1.103::*=0
WA_TRUST::*::127.0.0.1::*=1
A connection to the Agent is allowed only if the first WA_TRUST statement that is matched specifies 1 for the trust value. If no match is found, or the trust value of the first matching statement is 0 (zero), a connection is not allowed.
Any or all of the operands of the WA_TRUST statement may contain generic mask specifications (not regular expressions).
The trust statements are used when agent security is active (+u) or trust mode (-trust) is in affect. See How can I enable agent trust without enabling user authentication?