The terminology used within the documentation and software may require some clarification. The terminology is used regularly within RSBAC logfiles too. RSBAC makes use of three important concepts: Subjects, Objects and Requests. An instance of an Object is called a Target, object classes are sometimes called Target Types.
on a Linux system a RSBAC subject is equivalent to a process that wants to perform some type of action on an object (for example memory or a file);
an object (i.e. memory, disk) will be an instance of an object class. Sometimes an object class is referred to as a target type and the instance of an object class is sometimes referred to as a 'target'. Hence the term 'target' and 'object' are equivalents. For example the file /etc/passwd is an object (target) of type (target type, object class) FILE;
and finally a request is an abstraction for an action to be performed by a subject on an object (target). There are many dozens of requests, most of them are valid within more than one object class.
An example: a process wants to open the file /etc/passwd. The process has PID 1899 and has loaded the program stored in file '/usr/bin/vi'. Now /etc/passwd is an object of class FILE - or alternately we could say it's a target of target type FILE.
Using the RSBAC terminology we would say that a SUBJECT (the process) with caller_pid 1899 and caller_prog_name vi issued a REQUEST of type READ_WRITE_OPEN for OBJECT (target_type) FILE with tid (target id) /etc/passwd.