In the SIP messages ( RFC 3261 ) the SIP Warning header field is used to carry additional information about the status of a response.
This gives directly a clear overview of possible issues instead a manual time consuming search for Warning headers.
Per SIP method there is a Warnings tab indicating if the Warning header appears in the message flows :
Selecting the link indicated above in the red box brings up the corresponding SIP message flow
In this ladder diagram the Warning is immediately visible as it is emphasized in orange.