Add section to changes on triggering tasks at icp and fcp using regex…

src/reference/changes.rst

@@ -107,6 +107,23 @@ makes Cylc 7 "reset to waiting" use cases much easier:
 For more information on Cylc IDs, run ``cylc help id``.
 
 
+Selecting tasks at initial and final cycle point
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The initial and final cycle points in a workflow can now be referenced in
+commands using the ``^`` and ``$`` symbols, e.g:
+
+```bash
+# trigger "mytask" at the initial cycle point
+cylc trigger myworkflow//^/mytask
+
+# set required outputs for "mytask" at the final cycle point
+cylc set myworkflow//$/mytask
+
+# remove all tasks at the final cycle point
+cylc remove myworkflow//$
+
+
 Supported Python versions
 ^^^^^^^^^^^^^^^^^^^^^^^^^