Besides using the standard LIST values that we use, you can also define your own.
In certain makefiles, you'd put the following definition:
LIST=CONTROL
Then you can decide to build (or prevent from building) various subcomponents marked with CONTROL. This might be useful in a very big project, where compilation times are long and you need to test only a particular subsection, even though other subsections may be affected and would ordinarily be made.
For example, if you had marked two directories, robot_plc and pidloop, with the LIST=CONTROL macro within the makefile, you could then make just the robot_plc module:
make CONTROLLIST=robot_plc
or make both (note the use of quoting in the shell to capture the space character):
make "CONTROLLIST=robot_plc pidloop"
or make everything except the robot_plc module:
make EXCLUDE_CONTROLLIST=robot_plc