+With the option:--kernel option::
++
+* Process ID (PID).
+
+* Virtual process ID (VPID).
++
+This is the PID as seen by the application.
+
+* Unix user ID (UID).
+
+* Virtual Unix user ID (VUID).
++
+This is the UID as seen by the application.
+
+* Unix group ID (GID).
+
+* Virtual Unix group ID (VGID).
++
+This is the GID as seen by the application.
+
+With the option:--userspace option::
++
+* VPID
+* VUID
+* VGID
+
+When an event{nbsp}__E__ satisfies all the other explicit and implicit
+conditions of an event rule{nbsp}__ER__, __ER__ matches{nbsp}__E__ if
+the attributes of the process for which LTTng creates{nbsp}__E__ are
+*all* part of the inclusion sets of the tracing session and domain
+of{nbsp}__ER__.
+
+By default, on tracing session creation (see man:lttng-create(1)),
+all processes are allowed to record events. In other words, all the
+inclusion sets of the tracing session contain all the possible
+process attribute values.
+
+If a given inclusion set{nbsp}__IS__ contains all the possible values
+(option:--all option), then using the `track` command to add one or more
+values{nbsp}__V__ to{nbsp}__IS__:
+
+. Removes all the values from{nbsp}__IS__.
++
+This effectively makes{nbsp}__IS__ empty.
+
+. Adds{nbsp}__V__ to{nbsp}__IS__.
+
+Example: with the PID inclusion set, you can record all the system calls
+of a given process: