Cisco Cisco Computer Telephony Integration Option 9.0 Developer's Guide

To set a connection to Monitor mode, you must create a filter that specifies which 
events to monitor over that connection. The filter is a String; that String is the 
value for the CtiOs_IKeywordIDs.CTIOS_FILTER key in an Arguments 
instance. That Arguments instance is the argument for the SetMessageFilter() 
method.

The filter String you create to specify events to monitor must adhere to a specific 
syntax to accurately instruct the CTI OS Server to send the correct events. 

The general syntax for the filter String is as follows:

“key1=value1, value2, value3;key2=value4, value5, value6”

The filter String may also contain an asterisk (*), which is used as a wildcard 
to indicate any possible value. A prefix can be used in addition to * to narrow 
the results.  For example, using 10* will match 1001, 1002, 10003.However, 
CTI OS ignores any characters that follow the asterisk.  For example, using 
10*1will match both 1001and 1002.

The filter String must contain at least one key, and there must be at least one value 
for that key. However, a key may take multiple values, and the filter String may 
contain multiple keys.

Multiple values for a single key must be separated by commas (,). Multiple keys 
must be separated by semicolons (;).

Multiple keys in a single filter combine using a logical AND. That is, the filter 
is instructing CTI OS to send to this connection only events that meet all the 
criteria included in the filter.