Cisco Cisco Web Security Appliance S370 Guía Del Usuario

You can create a custom field for any header in a client request or a server 
response. For more information, see 

.

If the list of predefined access log and W3C log fields does not include all header 
information you want to log from HTTP/HTTPS transactions, you can type a user 
defined log field in the Custom Fields text box when you configure the access and 
W3C log subscriptions.

Custom log fields can be any data from any header sent from the client or the 
server. If a request or response does not include the header added to the log 
subscription, the log file includes a hyphen as the log field value.

 defines the syntax to use for access and W3C logs. 

Header from the 
client application

%<ClientHeaderName:

cs(ClientHeaderName) 

Header from the 
server

%<ServerHeaderName: 

sc(ServerHeaderName)

For example, if you want to log the If-Modified-Since header value in client 
requests, enter the following text in the Custom Fields box for a W3C log 
subscription:

cs(If-Modified-Since)