diff --git a/res/res_sip.c b/res/res_sip.c
index d6e31b4036..7bab9131e1 100644
--- a/res/res_sip.c
+++ b/res/res_sip.c
@@ -292,17 +292,26 @@
- Trust inbound CallerID information from endpoint
- This option determines whether res_sip will accept identification from the endpoint
- received in a P-Asserted-Identity or Remote-Party-ID header. If no,
- the configured Caller-ID from res_sip.conf will always be used as the identity for the
- endpoint.
+ Accept identification information received from this endpoint
+ This option determines whether Asterisk will accept
+ identification from the endpoint from headers such as P-Asserted-Identity
+ or Remote-Party-ID header. This option applies both to calls originating from the
+ endpoint and calls originating from Asterisk. If no, the
+ configured Caller-ID from res_sip.conf will always be used as the identity for
+ the endpoint.
- Trust endpoint with private CallerID information
- This option determines whether res_sip will send identification
- information to the endpoint that has been marked as private. If no,
- private Caller-ID information will not be forwarded to the endpoint.
+ Send private identification details to the endpoint.
+ This option determines whether res_sip will send private
+ identification information to the endpoint. If no,
+ private Caller-ID information will not be forwarded to the endpoint.
+ "Private" in this case refers to any method of restricting identification.
+ Example: setting callerid_privacy to any
+ prohib variation.
+ Example: If trust_id_inbound is set to
+ yes, the presence of a Privacy: id
+ header in a SIP request or response would indicate the identification
+ provided in the request is private.
Must be of type 'endpoint'.