diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 0e9c68f5..d5b8e6c2 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -9,11 +9,15 @@
   only_branch_master_parent_repo: &only_branch_master_parent_repo
     - 'master@saltstack-formulas/template-formula'
   # `stage`
+  stage_schema: &stage_schema 'schema'
   stage_lint: &stage_lint 'lint'
   stage_release: &stage_release 'release'
   stage_test: &stage_test 'test'
   # `image`
   image_commitlint: &image_commitlint 'myii/ssf-commitlint:11'
+  image_cuelang: &image_cuelang
+    name: 'myii/ssf-cue:0.3.2'    # instead of cuelang/cue
+    entrypoint: ['/bin/ash', '-c']
   image_dindruby: &image_dindruby 'myii/ssf-dind-ruby:2.7.1-r3'
   image_dindrubybionic: &image_dindrubybionic 'myii/ssf-dind-ruby-bionic:1_2.5.1'
   image_precommit: &image_precommit
@@ -41,6 +45,7 @@
 ###############################################################################
 stages:
   - *stage_lint
+  - *stage_schema
   - *stage_test
   - *stage_release
 variables:
@@ -100,6 +105,16 @@ rubocop:
   script:
     - 'rubocop -d -P -S --enable-pending-cops'
 
+cue:
+  allow_failure: true
+  stage: *stage_schema
+  image: *image_cuelang
+  variables:
+    DIR: 'TEMPLATE/parameters'
+    RULES: 'schema.cue'
+  script:
+    - 'cue vet -v $(find ${DIR} -name "*.yaml") ${DIR}/${RULES} --schema "#Values"'
+
 ###############################################################################
 # Define `test` template
 ###############################################################################
diff --git a/.yamllint b/.yamllint
index 5a060ef9..72dc99f2 100644
--- a/.yamllint
+++ b/.yamllint
@@ -10,12 +10,14 @@ extends: 'default'
 # 3. All YAML files under directory `node_modules/`, introduced during the Travis run
 # 4. Any SLS files under directory `test/`, which are actually state files
 # 5. Any YAML files under directory `.kitchen/`, introduced during local testing
+# 6. `kitchen.vagrant.yml`, which contains Embedded Ruby (ERB) template syntax
 ignore: |
   .cache/
   .git/
   node_modules/
   test/**/states/**/*.sls
   .kitchen/
+  kitchen.vagrant.yml
 
 yaml-files:
   # Default settings
diff --git a/CODEOWNERS b/CODEOWNERS
index f0221bfb..60a18662 100644
--- a/CODEOWNERS
+++ b/CODEOWNERS
@@ -39,6 +39,8 @@
 /Gemfile                                    @saltstack-formulas/ssf
 /Gemfile.lock                               @saltstack-formulas/ssf
 /kitchen.yml                                @saltstack-formulas/ssf
+/kitchen.vagrant.yml                        @saltstack-formulas/ssf
+/kitchen.windows.yml                        @saltstack-formulas/ssf
 /pre-commit_semantic-release.sh             @saltstack-formulas/ssf
 /release-rules.js                           @saltstack-formulas/ssf
 /release.config.js                          @saltstack-formulas/ssf
diff --git a/TEMPLATE/parameters/schema.cue b/TEMPLATE/parameters/schema.cue
new file mode 100755
index 00000000..6cb5c65a
--- /dev/null
+++ b/TEMPLATE/parameters/schema.cue
@@ -0,0 +1,61 @@
+// -*- coding: utf-8 -*-
+// vim: ft=yaml
+
+//
+// Data Constaints - Example from Saltstack-formulas
+//
+
+#Schema: #Values
+
+//
+// Rule
+//
+#Optional: {
+    pkg?:
+      name?: string
+    rootgroup?: string
+    hide_output?: bool
+    dir_mode?: =~"^0?[124567]{3}$" // any mode of length 3, with 0 prefix optional
+    mode?: =~"^0?[124567]{3}$" // any mode of length 3, with 0 prefix optional
+    config?:    string
+    service?: name?: string
+    subcomponent?: config?: string
+
+    // legacy
+    pip_pkg?: string
+    pkgs_add?: [...]
+    pips?: [...]
+
+    // Just here for testing
+    added_in_defaults?: string
+    winner?:            string
+        ...
+}
+
+//
+// Schema Name
+//
+#Values: {
+  values?: {...#Optional}
+}
+values?: {...#Values}   // Namespace
+
+
+//
+// Older schema
+//
+#TEMPLATE: {
+  TEMPLATE?: {...#Optional}
+}
+TEMPLATE?: {...#Optional}
+
+Debian?: #Optional
+Suse?: #Optional
+Gentoo?: #Optional
+Arch?: #Optional
+Alpine?: #Optional
+FreeBSD?: #Optional
+OpenBSD?: #Optional
+Solaris?: #Optional
+Windows?: #Optional
+MacOS?: #Optional