diff --git a/makefiles/consts.mk b/makefiles/consts.mk
index 043ec65..bac4362 100644
--- a/makefiles/consts.mk
+++ b/makefiles/consts.mk
@@ -13,16 +13,40 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+#
+# SPDX-FileCopyrightText: 2022-2023 Open Networking Foundation (ONF) and the ONF Contributors
+# SPDX-License-Identifier: Apache-2.0
 # -----------------------------------------------------------------------
 
-null         :=#
-space        :=$(null) $(null)
-dot          :=.
-HIDE         ?=@
+$(if $(DEBUG),$(warning ENTER))
 
-# use bash for pusdh/popd and quick failures.
-# virtual env(s) activate has undefined vars so no -u
-#   ^---+ verify this is still true
-export SHELL := bash -e -o pipefail
+# include makefiles/constants.mk
+export dot          :=.
+export null         :=#
+export space        := $(null) $(null)
+export quote-single := $(null)"$(null)#"
+export quote-double := $(null)'$(null)#'
+
+# [DEBUG] make {target} HIDE=
+HIDE        ?= @
+
+env-clean      ?= /usr/bin/env --ignore-environment
+xargs-n1       := xargs -0 -t -n1 --no-run-if-empty
+xargs-n1-clean := $(env-clean) $(xargs-n1)
+
+## -----------------------------------------------------------------------
+## Default shell:
+##   o set -e            enable error checking
+##   o set -u            report undefined errors
+##   o set -o pipefail   propogate shell pipeline failures.
+## -----------------------------------------------------------------------
+SHELL ?= /bin/bash
+have-shell-bash := $(filter bash,$(subst /,$(space),$(SHELL)))
+$(if $(have-shell-bash),$(null),\
+  $(eval export SHELL := bash -euo pipefail))
+
+export SHELL ?= bash -euo pipefail
+
+$(if $(DEBUG),$(warning LEAVE))
 
 # [EOF]
diff --git a/makefiles/include.mk b/makefiles/include.mk
new file mode 100644
index 0000000..3042488
--- /dev/null
+++ b/makefiles/include.mk
@@ -0,0 +1,41 @@
+# -*- makefile -*-
+# -----------------------------------------------------------------------
+# Copyright 2022-2023 Open Networking Foundation (ONF) and the ONF Contributors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-FileCopyrightText: 2022 Open Networking Foundation (ONF) and the ONF Contributors
+# SPDX-License-Identifier: Apache-2.0
+# -----------------------------------------------------------------------
+
+$(if $(DEBUG),$(warning ENTER))
+
+# OPT_ROOT    ?= /opt/trainlab/current
+# OPT_MAKEDIR := $(OPT_ROOT)/makefiles
+# MAKEDIR     ?= $(OPT_MAKEDIR)
+
+ONF_MAKE ?= $(MAKEDIR)# [TODO] -- local and library makefiles/ needed.
+ONF_MAKE ?= $(error ONF_MAKE= is required)
+
+include $(ONF_MAKE)/consts.mk
+include $(ONF_MAKE)/help/include.mk
+
+include $(ONF_MAKE)/virtualenv.mk#        # lint-{jjb,python} depends on venv
+include $(ONF_MAKE)/lint/include.mk
+include $(ONF_MAKE)/todo.mk
+include $(MAKEDIR)/patches/include.mk#    # Patch when python 3.10+ in use
+include $(ONF_MAKE)/help/variables.mk
+
+$(if $(DEBUG),$(warning LEAVE))
+
+# [EOF]
diff --git a/makefiles/lint/doc8.mk b/makefiles/lint/doc8.mk
new file mode 100644
index 0000000..e0594df
--- /dev/null
+++ b/makefiles/lint/doc8.mk
@@ -0,0 +1,79 @@
+# -*- makefile -*-
+# -----------------------------------------------------------------------
+# Copyright 2017-2022 Open Networking Foundation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# -----------------------------------------------------------------------
+
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+.PHONY: lint-doc8 lint-doc8-all lint-doc8-modified
+
+have-rst-files := $(if $(strip $(RST_SOURCE)),true)
+RST_SOURCE     ?= $(error RST_SOURCE= is required)
+
+## -----------------------------------------------------------------------
+## -----------------------------------------------------------------------
+ifndef NO-LINT-DOC8
+  lint-doc8-mode := $(if $(have-doc8-files),modified,all)
+  lint : lint-doc8-$(lint-doc8-mode)
+endif# NO-LINT-DOC8
+
+# Consistent targets across lint makefiles
+lint-doc8-all      : lint-doc8
+lint-doc8-modified : lint-doc8
+
+## -----------------------------------------------------------------------
+## -----------------------------------------------------------------------
+lint-doc8-excl += --ignore-path '$(venv-name)'
+lint-doc8-excl += --ignore-path '$(BUILDDIR)'
+
+# YUCK! -- overhead
+#   o Submodule(s) use individual/variant virtualenv install paths.
+#   o Exclude special snowflakes to enable library makefile use.
+#   o [TODO] Use makefiles/virtualenv.mk to avoid duplication.
+
+lint-doc8-excl += --ignore-path '*/venv_cord'
+lint-doc8-excl += --ignore-path '*/vst_venv'
+
+lint-doc8-excl += --ignore-path './cord-tester'
+lint-doc8-excl += --ignore-path './repos/cord-tester'
+
+lint-doc8-excl += --ignore-path './bbsim/internal/bbsim/responders/sadis/dp.txt'
+lint-doc8-excl += --ignore-path './repos/bbsim/internal/bbsim/responders/sadis/dp.txt'
+lint-doc8-excl += --ignore-path './repos/voltha-helm-charts/voltha-infra/templates/NOTES.txt'
+lint-doc8-excl += --ignore-path './voltha-helm-charts/voltha-infra/templates/NOTES.txt'
+
+lint-doc8-args += --max-line-length 120
+
+lint-doc8: $(venv-activate-script)
+	@echo
+	@echo '** -----------------------------------------------------------------------'
+	@echo '** doc8 *.rst syntax checking'
+	@echo '** -----------------------------------------------------------------------'
+	$(activate) && doc8 --version
+	@echo
+	$(activate) && doc8 $(lint-doc8-excl) $(lint-doc8-args) .
+
+## -----------------------------------------------------------------------
+## Intent: Display command usage
+## -----------------------------------------------------------------------
+help::
+	@echo '  lint-doc8          Syntax check python using the doc8 command'
+  ifdef VERBOSE
+	@echo '  lint-doc8-all       doc8 checking: exhaustive'
+	@echo '  lint-doc8-modified  doc8 checking: only modified'
+  endif
+
+# [EOF]
diff --git a/makefiles/lint/include.mk b/makefiles/lint/include.mk
index 0f653c9..96f6bce 100644
--- a/makefiles/lint/include.mk
+++ b/makefiles/lint/include.mk
@@ -15,12 +15,29 @@
 # limitations under the License.
 # -----------------------------------------------------------------------
 
+# -----------------------------------------------------------------------
+# Intent: Display help banner early before library lint help targets.
+# -----------------------------------------------------------------------
 help::
 	@echo
 	@echo "[LINT]"
 
+## Disable python linting in bulk ?
+ifdef NO-LINT-PYTHON
+  NO-LINT-FLAKE8 := true
+  NO-LINT-PYLINT := true
+endif
+
+# Define early else {flake8,pylint}.mk will complain:
+#    PYTHON_FILES ?= $(error)
+have-python-files := $(if $(strip $(PYTHON_FILES)),true)
+
+##--------------------##
+##---]  INCLUDES  [---##
+##--------------------##
+include $(MAKEDIR)/lint/doc8.mk
 include $(MAKEDIR)/lint/json.mk
-include $(MAKEDIR)/lint/python.mk
+include $(MAKEDIR)/lint/python/include.mk
 include $(MAKEDIR)/lint/robot.mk
 include $(MAKEDIR)/lint/shell.mk
 include $(MAKEDIR)/lint/yaml.mk
diff --git a/makefiles/lint/json.mk b/makefiles/lint/json.mk
index e67fee1..1deeaba 100644
--- a/makefiles/lint/json.mk
+++ b/makefiles/lint/json.mk
@@ -1,8 +1,8 @@
 # -*- makefile -*-
 # -----------------------------------------------------------------------
-# Copyright 2017-2023 Open Networking Foundation
+# Copyright 2017-2023 Open Networking Foundation (ONF) and the ONF Contributors
 #
-# Licensed under the Apache License, Version 2.0 (the "License");
+# Licensed under the Apache License, Version 2.0 (the "License")
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
@@ -15,21 +15,78 @@
 # limitations under the License.
 # -----------------------------------------------------------------------
 
-JSON_FILES ?= $(error JSON_FILES= is rqeuired)
+$(if $(DEBUG),$(warning ENTER))
 
-.PHONY: lint-json
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+.PHONY: lint-json lint-json-all lint-json-modified
 
-lint : lint-json
+have-json-files := $(if $(strip $(JSON_FILES)),true)
+JSON_FILES      ?= $(error JSON_FILES= required)
 
-lint-json: vst_venv
-	source ./$</bin/activate \
-	    ; set -u \
-	    ; for jsonfile in $(JSON_FILES); do \
-		echo "Validating json file: $$jsonfile" ;\
-		python -m json.tool $$jsonfile > /dev/null ;\
-	done
+## -----------------------------------------------------------------------
+## Intent: Use the json command to perform syntax checking.
+##   o If UNSTABLE=1 syntax check all sources
+##   o else only check sources modified by the developer.
+## Usage:
+##   % make lint UNSTABLE=1
+##   % make lint-json-all
+## -----------------------------------------------------------------------
+ifndef NO-LINT-JSON
+  lint-json-mode := $(if $(have-json-files),modified,all)
+  lint : lint-json-$(lint-json-mode)
+endif# NO-LINT-JSON
 
+## -----------------------------------------------------------------------
+## Intent: exhaustive json syntax checking
+## -----------------------------------------------------------------------
+json-find-args := $(null)
+json-find-args += -name '$(venv-name)'
+lint-json-all:	
+	$(HIDE)$(MAKE) --no-print-directory lint-json-install
+
+	$(activate)\
+ && find . \( $(json-find-args) \) -prune -o -name '*.json' -print0 \
+	| $(xargs-n1) python -m json.tool > /dev/null ;\
+
+## -----------------------------------------------------------------------
+## Intent: check deps for format and python3 cleanliness
+## Note:
+##   json --py3k option no longer supported
+## -----------------------------------------------------------------------
+lint-json-modified: $(venv-activate-script)
+	$(HIDE)$(MAKE) --no-print-directory lint-json-install
+
+	$(activate)\
+ && for jsonfile in $(JSON_FILES); do \
+        echo "Validating json file: $$jsonfile" ;\
+        python -m json.tool $$jsonfile > /dev/null ;\
+    done
+
+## -----------------------------------------------------------------------
+## Intent:
+## -----------------------------------------------------------------------
+.PHONY: lint-json-install
+lint-json-install: $(venv-activate-script)
+	@echo
+	@echo "** -----------------------------------------------------------------------"
+	@echo "** json syntax checking"
+	@echo "** -----------------------------------------------------------------------"
+#	$(activate) && pip install --upgrade json.tool
+#       $(activate) && python -m json.tool --version (?-howto-?)
+	@echo
+
+## -----------------------------------------------------------------------
+## Intent: Display command usage
+## -----------------------------------------------------------------------
 help::
-	@echo "  lint-json            Syntax check json sources"
+	@echo '  lint-json          Syntax check python using the json command'
+  ifdef VERBOSE
+	@echo '  lint-json-all       json checking: exhaustive'
+	@echo '  lint-json-modified  json checking: only modified'
+  endif
+
+$(if $(DEBUG),$(warning LEAVE))
 
 # [EOF]
diff --git a/makefiles/lint/python/flake8.mk b/makefiles/lint/python/flake8.mk
new file mode 100644
index 0000000..bb474a9
--- /dev/null
+++ b/makefiles/lint/python/flake8.mk
@@ -0,0 +1,85 @@
+# -*- makefile -*-
+# -----------------------------------------------------------------------
+# Copyright 2017-2023 Open Networking Foundation (ONF) and the ONF Contributors
+#
+# Licensed under the Apache License, Version 2.0 (the "License")
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# -----------------------------------------------------------------------
+
+$(if $(DEBUG),$(warning ENTER))
+
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+.PHONY: lint-flake8 lint-flake8-all lint-flake8-modified
+
+PYTHON_FILES      ?= $(error PYTHON_FILES= required)
+
+## -----------------------------------------------------------------------
+## Intent: Use the flake8 command to perform syntax checking.
+## Usage:
+##   % make lint
+##   % make lint-flake8-all
+## -----------------------------------------------------------------------
+ifndef NO-LINT-FLAKE8
+  lint-flake8-mode := $(if $(have-python-files),modified,all)
+  lint : lint-flake8-$(lint-flake8-mode)
+endif# NO-LINT-FLAKE8
+
+## -----------------------------------------------------------------------
+## Intent: exhaustive flake8 syntax checking
+## -----------------------------------------------------------------------
+lint-flake8-all: $(venv-activate-script)
+	$(HIDE)$(MAKE) --no-print-directory lint-flake8-install
+
+	$(activate)\
+ && find . \( -name '$(venv-name)' \) -prune -o -name '*.py' -print0 \
+	| $(xargs-n1) flake8 --max-line-length=99 --count
+
+## -----------------------------------------------------------------------
+## Intent: check deps for format and python3 cleanliness
+## Note:
+##   pylint --py3k option no longer supported
+## -----------------------------------------------------------------------
+lint-flake8-modified: $(venv-activate-script)
+	$(HIDE)$(MAKE) --no-print-directory lint-flake8-install
+
+	$(activate)\
+ && flake8 --max-line-length=99 --count $(PYTHON_FILES)
+
+## -----------------------------------------------------------------------
+## Intent:
+## -----------------------------------------------------------------------
+.PHONY: lint-flake8-install
+lint-flake8-install: $(venv-activate-script)
+	@echo
+	@echo "** -----------------------------------------------------------------------"
+	@echo "** python flake8 syntax checking"
+	@echo "** -----------------------------------------------------------------------"
+	$(activate) && pip install --upgrade flake8
+	$(activate) && flake8 --version
+	@echo
+
+## -----------------------------------------------------------------------
+## Intent: Display command usage
+## -----------------------------------------------------------------------
+help::
+	@echo '  lint-flake8          Syntax check python using the flake8 command'
+  ifdef VERBOSE
+	@echo '  $(MAKE) lint-pylint PYTHON_FILES=...'
+	@echo '  lint-flake8-modified  flake8 checking: only modified'
+	@echo '  lint-flake8-all       flake8 checking: exhaustive'
+  endif
+
+$(if $(DEBUG),$(warning LEAVE))
+
+# [EOF]
diff --git a/makefiles/lint/python.mk b/makefiles/lint/python/include.mk
similarity index 62%
rename from makefiles/lint/python.mk
rename to makefiles/lint/python/include.mk
index d8bdfe0..69811a5 100644
--- a/makefiles/lint/python.mk
+++ b/makefiles/lint/python/include.mk
@@ -1,6 +1,6 @@
 # -*- makefile -*-
 # -----------------------------------------------------------------------
-# Copyright 2017-2023 Open Networking Foundation
+# Copyright 2017-2023 Open Networking Foundation (ONF) and the ONF Contributors
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -15,20 +15,13 @@
 # limitations under the License.
 # -----------------------------------------------------------------------
 
-PYTHON_FILES ?= $(error PYTHON_FILES= is required)
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+$(if $(UNSTABLE),$(eval lint-python-all := true))
 
-.PHONY: lint-python
-
-lint : lint-python
-
-# check deps for format and python3 cleanliness
-lint-python: vst_venv
-	source ./$</bin/activate \
-	    ; set -u \
-	    ; pylint --py3k $(PYTHON_FILES) \
-	    ; flake8 --max-line-length=99 --count $(PYTHON_FILES)
-
-help::
-	@echo "  lint-python          Syntax check using pylint and flake8"
+include $(MAKEDIR)/lint/python/flake8.mk
+include $(MAKEDIR)/lint/python/pylint.mk
+# include $(MAKEDIR)/lint/python/tox.mk
 
 # [EOF]
diff --git a/makefiles/lint/python/pylint.mk b/makefiles/lint/python/pylint.mk
new file mode 100644
index 0000000..9dc1c7c
--- /dev/null
+++ b/makefiles/lint/python/pylint.mk
@@ -0,0 +1,89 @@
+# -*- makefile -*-
+# -----------------------------------------------------------------------
+# Copyright 2017-2023 Open Networking Foundation (ONF) and the ONF Contributors
+#
+# Licensed under the Apache License, Version 2.0 (the "License")
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# -----------------------------------------------------------------------
+
+$(if $(DEBUG),$(warning ENTER))
+
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+.PHONY: lint-pylint lint-pylint-all lint-pylint-modified
+
+PYTHON_FILES      ?= $(error PYTHON_FILES= required)
+
+## -----------------------------------------------------------------------
+## Intent: Use the pylint command to perform syntax checking.
+##   o If UNSTABLE=1 syntax check all sources
+##   o else only check sources modified by the developer.
+## Usage:
+##   % make lint UNSTABLE=1
+##   % make lint-pylint-all
+## -----------------------------------------------------------------------
+ifndef NO-LINT-PYLINT
+  lint-pylint-mode := $(if $(have-python-files),modified,all)
+  lint : lint-pylint-$(lint-pylint-mode)
+endif# NO-LINT-PYLINT
+
+## -----------------------------------------------------------------------
+## Intent: exhaustive pylint syntax checking
+## -----------------------------------------------------------------------
+pylint-find-args := $(null)
+pylint-find-args += -name '$(venv-name)'
+pylint-find-args += -o -name 'patches'
+lint-pylint-all: $(venv-activate-script)
+	$(MAKE) --no-print-directory lint-pylint-install
+
+	$(activate)\
+ && find . \( $(pylint-find-args) \) -prune -o -name '*.py' -print0 \
+	| $(xargs-n1) pylint
+
+## -----------------------------------------------------------------------
+## Intent: check deps for format and python3 cleanliness
+## Note:
+##   pylint --py3k option no longer supported
+## -----------------------------------------------------------------------
+lint-pylint-modified: $(venv-activate-script)
+	$(MAKE) --no-print-directory lint-pylint-install
+
+	$(activate) && pylint $(PYTHON_FILES)
+
+## -----------------------------------------------------------------------
+## Intent:
+## -----------------------------------------------------------------------
+.PHONY: lint-pylint-install
+lint-pylint-install: $(venv-activate-script)
+	@echo
+	@echo "** -----------------------------------------------------------------------"
+	@echo "** python pylint syntax checking"
+	@echo "** -----------------------------------------------------------------------"
+	$(activate) && pip install --upgrade pylint
+	$(activate) && pylint --version
+	@echo
+
+## -----------------------------------------------------------------------
+## Intent: Display command usage
+## -----------------------------------------------------------------------
+help::
+	@echo '  lint-pylint          Syntax check python using the pylint command'
+  ifdef VERBOSE
+	@echo '  $(MAKE) lint-pylint PYTHON_FILES=...'
+	@echo '  lint-pylint-modified  pylint checking: only modified'
+	@echo '  lint-pylint-all       pylint checking: exhaustive'
+  endif
+
+$(if $(DEBUG),$(warning LEAVE))
+
+# [EOF]
diff --git a/makefiles/lint/robot.mk b/makefiles/lint/robot.mk
index 1c7119f..fa8175c 100644
--- a/makefiles/lint/robot.mk
+++ b/makefiles/lint/robot.mk
@@ -1,8 +1,8 @@
 # -*- makefile -*-
 # -----------------------------------------------------------------------
-# Copyright 2017-2023 Open Networking Foundation
+# Copyright 2017-2023 Open Networking Foundation (ONF) and the ONF Contributors
 #
-# Licensed under the Apache License, Version 2.0 (the "License");
+# Licensed under the Apache License, Version 2.0 (the "License")
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
@@ -15,7 +15,15 @@
 # limitations under the License.
 # -----------------------------------------------------------------------
 
-ROBOT_FILES ?= $(error ROBOT_FILES= is required)
+$(if $(DEBUG),$(warning ENTER))
+
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+.PHONY: lint-robot lint-robot-all lint-robot-modified
+
+have-robot-files := $(if $(ROBOT_FILES),true)
+ROBOT_FILES      ?= $(error ROBOT_FILES= required)
 
 LINT_ARGS ?= --verbose --configure LineTooLong:130 -e LineTooLong \
              --configure TooManyTestSteps:65 -e TooManyTestSteps \
@@ -25,17 +33,62 @@
              --configure FileTooLong:2000 -e FileTooLong \
              -e TrailingWhitespace
 
+## -----------------------------------------------------------------------
+## Intent: Use the robot command to perform syntax checking.
+##   % make lint
+##   % make lint-robot-all
+##   % make lint-robot-modified
+## -----------------------------------------------------------------------
+ifndef NO-LINT-ROBOT
+  lint-robot-mode := $(if $(have-robot-files),modified,all)
+  lint : lint-robot-$(lint-robot-mode)
+endif# NO-LINT-ROBOT
 
-.PHONY: lint-robot
+## -----------------------------------------------------------------------
+## Intent: exhaustive robot syntax checking
+## -----------------------------------------------------------------------
+lint-robot-all:
+	$(HIDE)$(MAKE) --no-print-directory rflint-install
 
-lint : lint-robot
+	$(activate)\
+ && find . \( -iname '*.robot' \) -print0 \
+	| $(xargs-n1) rflint $(LINT_ARGS)
 
-lint-robot: vst_venv
-	source ./$</bin/activate \
-	    ; set -u \
-	    ; rflint $(LINT_ARGS) $(ROBOT_FILES)
+## -----------------------------------------------------------------------
+## Intent: check deps for format and python3 cleanliness
+## Note:
+##   robot --py3k option no longer supported
+## -----------------------------------------------------------------------
+lint-robot-modified: $(venv-activate-script)
+	$(HIDE)$(MAKE) --no-print-directory rflint-install
 
+	$(activate) && rflint $(LINT_ARGS) $(ROBOT_FILES)
+
+## -----------------------------------------------------------------------
+## Intent: Install the rflint command for syntax checking.
+##   Note: requirements.txt pip install not used here ATM due to implicit
+##         per-repository dependency config to enable checking.
+## -----------------------------------------------------------------------
+rflint-install: $(venv-activate-script)
+	@echo
+	@echo "** -----------------------------------------------------------------------"
+	@echo "** robot syntax checking"
+	@echo "** -----------------------------------------------------------------------"
+	$(activate)\
+ && pip install --upgrade robotframework-lint
+	$(activate) && rflint --version
+	@echo
+
+## -----------------------------------------------------------------------
+## Intent: Display command usage
+## -----------------------------------------------------------------------
 help::
-	@echo "  lint-robot           Syntax check robot sources using rflint"
+	@echo '  lint-robot          Syntax check python using the robot command'
+  ifdef VERBOSE
+	@echo '  lint-robot-all       robot checking: exhaustive'
+	@echo '  lint-robot-modified  robot checking: only modified'
+  endif
+
+$(if $(DEBUG),$(warning LEAVE))
 
 # [EOF]
diff --git a/makefiles/lint/shell.mk b/makefiles/lint/shell.mk
index 9923b72..3c04539 100644
--- a/makefiles/lint/shell.mk
+++ b/makefiles/lint/shell.mk
@@ -1,8 +1,8 @@
 # -*- makefile -*-
 # -----------------------------------------------------------------------
-# Copyright 2017-2023 Open Networking Foundation
+# Copyright 2017-2023 Open Networking Foundation (ONF) and the ONF Contributors
 #
-# Licensed under the Apache License, Version 2.0 (the "License");
+# Licensed under the Apache License, Version 2.0 (the "License")
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
@@ -15,19 +15,73 @@
 # limitations under the License.
 # -----------------------------------------------------------------------
 
-JSON_FILES ?= $(error JSON_FILES= is required)
+$(if $(DEBUG),$(warning ENTER))
 
-.PHONY: lint-shell
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+.PHONY: lint-shell lint-shell-all lint-shell-modified
 
-lint : lint-shell
+have-shell-sources := $(if $(strip $(SHELL_SOURCES)),true)
+SHELL_SOURCES      ?= $(error SHELL_SOURCES= required)
 
-lint-shell:
+## -----------------------------------------------------------------------
+## Intent: Use the shell command to perform syntax checking.
+##   % make lint
+##   % make lint-shell-all
+## -----------------------------------------------------------------------
+ifndef NO-LINT-SHELL
+  lint-shell-mode := $(if $(have-shell-sources),modified,all)
+  lint : lint-shell-$(lint-shell-mode)
+endif# NO-LINT-SHELL
+
+## -----------------------------------------------------------------------
+## Intent: exhaustive shell syntax checking
+## -----------------------------------------------------------------------
+shellcheck-find-args := $(null)
+shellcheck-find-args += -name '$(venv-name)'
+shellcheck-find-args += -o -name 'staging'
+lint-shell-all:
+	$(MAKE) --no-print-directory lint-shellcheck-install
+
+	find . \( $(shellcheck-find-args) \) -prune -name '*.sh' -print0 \
+	    | $(xargs-n1-clean) shellcheck
+
+## -----------------------------------------------------------------------
+## Intent: check deps for format and python3 cleanliness
+## Note:
+##   shell --py3k option no longer supported
+## -----------------------------------------------------------------------
+lint-shell-modified:
+	$(MAKE) --no-print-directory lint-shell-install
+
+	shellcheck $(SHELL_SOURCES)
+
+## -----------------------------------------------------------------------
+## Intent:
+## -----------------------------------------------------------------------
+.PHONY: lint-shellcheck-install
+lint-shellcheck-install:
+	@echo
+	@echo "** -----------------------------------------------------------------------"
+	@echo '** command shell syntax checking'
+	@echo "** -----------------------------------------------------------------------"
+
+        # {apt-get,rpm,yum} install shellcheck
 	shellcheck --version
-	find . \( -name 'staging' -o -name 'vst_venv' \) -prune \
-	    -o -name '*.sh' ! -name 'activate.sh' -print0 \
-	| xargs -0 -n1 shellcheck
+	@echo
 
+## -----------------------------------------------------------------------
+## Intent: Display command usage
+## -----------------------------------------------------------------------
 help::
-	@echo "  lint-shell           Syntax check bash,bourne,etc sources"
+	@echo '  lint-shell          Syntax check sources using shellcheck'
+  ifdef VERBOSE
+	@echo '  $(MAKE) lint-shell SHELL_SOURCES=...'
+	@echo '  lint-shell-modified  shell checking: only modified'
+	@echo '  lint-shell-all       shell checking: exhaustive'
+  endif
+
+$(if $(DEBUG),$(warning LEAVE))
 
 # [EOF]
diff --git a/makefiles/lint/yaml.mk b/makefiles/lint/yaml.mk
index c875686..566ac18 100644
--- a/makefiles/lint/yaml.mk
+++ b/makefiles/lint/yaml.mk
@@ -1,8 +1,8 @@
 # -*- makefile -*-
 # -----------------------------------------------------------------------
-# Copyright 2017-2023 Open Networking Foundation
+# Copyright 2017-2023 Open Networking Foundation (ONF) and the ONF Contributors
 #
-# Licensed under the Apache License, Version 2.0 (the "License");
+# Licensed under the Apache License, Version 2.0 (the "License")
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
@@ -15,18 +15,68 @@
 # limitations under the License.
 # -----------------------------------------------------------------------
 
-YAML_FILES ?= $(error YAML_FILES= is required)
+$(if $(DEBUG),$(warning ENTER))
 
-.PHONY: lint-yaml
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+.PHONY: lint-yaml lint-yaml-all lint-yaml-modified
 
-lint : lint-yaml
+have-yaml-files := $(if $(strip $(YAML_FILES)),true)
+YAML_FILES      ?= $(error YAML_FILES= is required)
 
-lint-yaml: vst_venv
-	source ./$</bin/activate \
-	    ; set -u \
-	    ; yamllint -s $(YAML_FILES)
+## -----------------------------------------------------------------------
+## Intent: Use the yaml command to perform syntax checking.
+##   o If UNSTABLE=1 syntax check all sources
+##   o else only check sources modified by the developer.
+## Usage:
+##   % make lint UNSTABLE=1
+##   % make lint-yaml-all
+## -----------------------------------------------------------------------
+ifndef NO-LINT-YAML
+  lint-yaml-mode := $(if $(have-yaml-files),modified,all)
+  lint : lint-yaml-$(lint-yaml-mode)
+endif# NO-LINT-YAML
 
+## -----------------------------------------------------------------------
+## Intent: exhaustive yaml syntax checking
+## -----------------------------------------------------------------------
+lint-yaml-all:
+	$(HIDE)$(MAKE) --no-print-directory lint-yaml-install
+
+	find . \( -iname '*.yaml' -o -iname '*.yml' \) -print0 \
+	    | $(xargs-n1-clean) yamllint --strict
+
+## -----------------------------------------------------------------------
+## Intent: check deps for format and python3 cleanliness
+## Note:
+##   yaml --py3k option no longer supported
+## -----------------------------------------------------------------------
+lint-yaml-modified:
+	$(HIDE)$(MAKE) --no-print-directory lint-yaml-install
+	yamllint -s $(YAML_FILES)
+
+## -----------------------------------------------------------------------
+## Intent:
+## -----------------------------------------------------------------------
+lint-yaml-install:
+	@echo
+	@echo "** -----------------------------------------------------------------------"
+	@echo "** yaml syntax checking"
+	@echo "** -----------------------------------------------------------------------"
+	yamllint --version
+	@echo
+
+## -----------------------------------------------------------------------
+## Intent: Display command usage
+## -----------------------------------------------------------------------
 help::
-	@echo "  lint-yaml            Syntax check yaml source using yamllint"
+	@echo '  lint-yaml          Syntax check python using the yaml command'
+  ifdef VERBOSE
+	@echo '  lint-yaml-all       yaml checking: exhaustive'
+	@echo '  lint-yaml-modified  yaml checking: only modified'
+  endif
+
+$(if $(DEBUG),$(warning LEAVE))
 
 # [EOF]
diff --git a/makefiles/patches/include.mk b/makefiles/patches/include.mk
index 2bd1bfd..4accdf2 100644
--- a/makefiles/patches/include.mk
+++ b/makefiles/patches/include.mk
@@ -27,7 +27,9 @@
 patch-gather-args += '-e' 'from collections import Mapping'
 patch-gather-args += '-e' 'from collections import MutableMapping'
 
-VENV_NAME   ?= $(error $(MAKE) VENV_NAME= is required)
+# Defined by [Mm]akefile or makefiles/virtualenv.mk
+venv-name   ?= $(error $(MAKE) venv-name= is required)
+
 PATCH_PATH  ?= $(error $(MAKE) PATCH_PATH= is required)
 
 ## -----------------------------------------------------------------------
@@ -38,7 +40,7 @@
 ## -----------------------------------------------------------------------
 ## -----------------------------------------------------------------------
 patch-diff:
-	$(HIDE)diff -qr staging $(VENV_NAME) \
+	$(HIDE)diff -qr staging $(venv-name) \
 	    | awk '{print "# diff -Naur "$$2" "$$4}' \
 	    | tee $@.log
 
@@ -46,16 +48,16 @@
 ## -----------------------------------------------------------------------
 patch-create:
 	mkdir -p patches/$(PATCH_PATH)
-	diff -Naur staging/$(PATCH_PATH) $(VENV_NAME)/$(PATCH_PATH) | tee patches/$(PATCH_PATH)/patch
+	diff -Naur staging/$(PATCH_PATH) $(venv-name)/$(PATCH_PATH) | tee patches/$(PATCH_PATH)/patch
 	exit 1
 
 ## -----------------------------------------------------------------------
 ## -----------------------------------------------------------------------
 patch-init:
-	find "$(VENV_NAME)" -name '__pycache__' -type d -print0 \
+	find "$(venv-name)" -name '__pycache__' -type d -print0 \
 	    | xargs -I'{}' --null --no-run-if-empty $(RM) -r {}
 	mkdir -p staging
-	rsync -rv --checksum "$(VENV_NAME)/." "staging/."
+	rsync -rv --checksum "$(venv-name)/." "staging/."
 	@echo "Modify files beneath staging/ to create a patch source"
 
 # [SEE ALSO]
diff --git a/makefiles/todo.mk b/makefiles/todo.mk
new file mode 100644
index 0000000..b122a9e
--- /dev/null
+++ b/makefiles/todo.mk
@@ -0,0 +1,35 @@
+# -*- makefile -*-
+# -----------------------------------------------------------------------
+# Copyright 2022-2023 Open Networking Foundation (ONF) and the ONF Contributors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-FileCopyrightText: 2022-2023 Open Networking Foundation (ONF) and the ONF Contributors
+# SPDX-License-Identifier: Apache-2.0
+# -----------------------------------------------------------------------
+
+$(if $(DEBUG),$(warning ENTER))
+
+## -----------------------------------------------------------------------
+## -----------------------------------------------------------------------
+todo ::
+	@echo '[TODO]'
+
+## -----------------------------------------------------------------------
+## -----------------------------------------------------------------------
+help ::
+	@echo '  todo                Display future enhancement list.'
+
+$(if $(DEBUG),$(warning LEAVE))
+
+# [EOF]
diff --git a/makefiles/virtualenv.mk b/makefiles/virtualenv.mk
index d54bfda..bcda734 100644
--- a/makefiles/virtualenv.mk
+++ b/makefiles/virtualenv.mk
@@ -1,6 +1,6 @@
 # -*- makefile -*-
 ## -----------------------------------------------------------------------
-# Copyright 2017-2023 Open Networking Foundation
+# Copyright 2017-2023 Open Networking Foundation (ONF) and the ONF Contributors
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -15,18 +15,73 @@
 # limitations under the License.
 ## -----------------------------------------------------------------------
 
-# virtualenv for the robot tools
-# VOL-2724 Invoke pip via python3 to avoid pathname too long on QA jobs
+$(if $(DEBUG),$(warning ENTER))
 
-vst_venv-2 : vst_venv/bin/activate requirements.txt
+##-------------------##
+##---]  GLOBALS  [---##
+##-------------------##
+.PHONY: venv
 
-vst_venv/bin/activate: requirements.txt
-	virtualenv -p python3 $@
+##------------------##
+##---]  LOCALS  [---##
+##------------------##
+venv-name            ?= .venv#                            # default install directory
+venv-abs-path        := $(PWD)/$(venv-name)
 
-	@echo	
-	@[ -r requirements.txt ]\
-  && { echo "python -m pip install -r requirements.txt"; }\
-  && source ./$@/bin/activate\
-  && python -m pip install -r requirements.txt
+venv-activate-script := $(venv-name)/bin/activate#        # dependency
+
+# Intent: activate= is a macro for accessing the virtualenv activation script#
+#  Usage: $(activate) && python
+activate             ?= set +u && source $(venv-activate-script) && set -u
+
+## -----------------------------------------------------------------------
+## Intent: Activate script path dependency
+## Usage:
+##    o place on the right side of colon as a target dependency
+##    o When the script does not exist install the virtual env and display.
+## -----------------------------------------------------------------------
+$(venv-activate-script):
+	@echo
+	@echo "============================="
+	@echo "Installing python virtual env"
+	@echo "============================="
+	virtualenv -p python3 $(venv-name)
+	$(activate) && python -m pip install --upgrade pip
+	$(activate) && pip install --upgrade setuptools
+	$(activate) && { [[ -r requirements.txt ]] && python -m pip install -r requirements.txt; }
+	$(activate) && python --version
+
+ifndef NO_PYTHON_UPGRADE_PATCHING
+	@echo
+	@echo '** -----------------------------------------------------------------------'
+	@echo '** Applying python virtualenv patches as needed (v3.10+)'
+	@echo '** -----------------------------------------------------------------------'
+	./patches/python_310_migration.sh '--venv' '$(venv-name)' 'apply'
+endif
+
+## -----------------------------------------------------------------------
+## Intent: Explicit named installer target w/o dependencies.
+##         Makefile targets should depend on venv-activate-script.
+## -----------------------------------------------------------------------
+venv: $(venv-activate-script)
+
+## -----------------------------------------------------------------------
+## Intent: Revert installation to a clean checkout
+## -----------------------------------------------------------------------
+sterile :: clean
+	$(RM) -r "$(venv-abs-path)"
+
+## -----------------------------------------------------------------------
+## -----------------------------------------------------------------------
+help ::
+	@echo
+	@echo '[VIRTUAL ENV]'
+	@echo '  venv                Create a python virtual environment'
+	@echo '    venv-name=        Subdir name for virtualenv install'
+	@echo '  venv-activate-script         make macro name'
+	@echo '      $$(target) dependency    install python virtualenv'
+	@echo '      source $$(macro) && cmd  configure env and run cmd'
+
+$(if $(DEBUG),$(warning LEAVE))
 
 # [EOF]