diff --git a/makefiles_include_mk.ex b/makefiles_include_mk.ex
index 1bad7af..3e79d0a 100644
--- a/makefiles_include_mk.ex
+++ b/makefiles_include_mk.ex
@@ -35,7 +35,7 @@
 ## Define vars based on relative import (normalize symlinks)
 ## Usage: include makefiles/onf/include.mk
 ## -----------------------------------------------------------------------
-onf-mk-abs    ?= $(abspath $(lastword $(MAKEFILE_LIST)))
+onf-mk-abs    := $(abspath $(lastword $(MAKEFILE_LIST)))
 onf-mk-top    := $(subst /include.mk,$(null),$(onf-mk-abs))
 onf-mk-lib    := $(onf-mk-top)/onf-lib/makefiles
 onf-mk-loc    := $(onf-mk-top)/local
@@ -56,6 +56,10 @@
 include $(onf-mk-lib)/include.mk
 include $(onf-mk-loc)/include.mk
 
+## -----------------------------------------------------------------------
+## Intent: Helper targets for maintaining git-submodules (repo:onf-make)
+## -----------------------------------------------------------------------
+
 ## -----------------------------------------
 ## Submodue init target for new repositories
 ## -----------------------------------------
@@ -65,9 +69,29 @@
 	cd $(dir $@) \
 	    && git submodule https://github.com/opencord/onf-make.git onf-lib
 
+## -----------------------------------------------------------------------
+## Intent: This target will update dependent git-submodule to the latest
+##         version available from the remote repository.  Subsequently
+##         a checkin will be needed to make the submodule update permanent.
+## -----------------------------------------------------------------------
 update-submodules:
 	git submodule foreach git pull
 
+## -----------------------------------------------------------------------
+## Intent: On-demand cloning of git submodule(s).
+## -----------------------------------------------------------------------
+## Trigger: include $(onf-mk-lib)/include.mk
+##   - When the make command attempts to include a makefile from the
+##     repo:onf-make submodule, this target/dependency will initialize
+##     and checkout all submodules the current repository depends on.
+## -----------------------------------------------------------------------
+$(onf-mk-lib)/include.mk:
+	@echo
+	@echo "** Checkout git submodule(s)"
+	@echo "** -----------------------------------------------------------------------"
+	git submodule update --init --recursive
+	@echo "** -----------------------------------------------------------------------"
+
 $(if $(DEBUG),$(warning LEAVE))
 
 # [EOF]