Processed Eric's merge request comments:

-Added header, author, purpose, description and link to Confluence.
-Improved comment and comment blocks.

.gitlab-ci.yml

+###############################################################################
+#
+# Copyright 2022
+# ASTRON (Netherlands Institute for Radio Astronomy) <http://www.astron.nl/>
+# P.O.Box 2, 7990 AA Dwingeloo, The Netherlands
+#
+# 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.
+#
+###############################################################################
+
+# Author:
+# . Daniel van der Schuur
+# Purpose:
+# . Define automated test stages for the HDL repository this file belongs to.
+# Description:
+# . See https://support.astron.nl/confluence/display/L2M/L3+SDP+Decision%3A+Gitlab+pipeline+automation+to+test+SDPFW+with+OPC+UA
+
 stages:
     - simulation
     - synthesis
@@ -5,7 +32,7 @@ stages:
 
 
 ###############################################################################
-# Simulation stage
+# HDL simulation stage
 ###############################################################################
 sim-compile:
     tags: 
@@ -25,11 +52,13 @@ sim-run:
     stage: simulation
     script:
         - echo "Running simulations"
-#        - test -f "build/info.txt" #this fails desite having artifact. Why?
-
+#        - test -f "build/info.txt" # This fails despite having artifact (see 
+                                    # sim-compile code block where a folder and
+                                    # file are generated and preserved by using
+                                    # 'artifacts').
 
 ###############################################################################
-# Synthesis stage
+# HDL synthesis stage
 ###############################################################################
 synth-compile:
     tags: