diff --git a/hilbert_config/hilbert_cli_config.py b/hilbert_config/hilbert_cli_config.py
index 04f0bf7..d0f5dfd 100644
--- a/hilbert_config/hilbert_cli_config.py
+++ b/hilbert_config/hilbert_cli_config.py
@@ -45,6 +45,29 @@
 PEDANTIC = False  # NOTE: to treat invalid values/keys as errors?
 INPUT_DIRNAME = './'  # NOTE: base location for external resources
 _SSH_CONFIG_PATH = None
+_HILBERT_STATION = '~/bin/hilbert-station'  # NOTE: client-side CLI tool (driver)
+_HILBERT_STATION_OPTIONS = ''  # -v/-q? -t/-d?
+_DRY_RUN_MODE = 0  # 0 - normal mode, 1 => server & client side dry-run mode!, 2 => server-side dry mode (no remote executions!),
+
+
+###############################################################
+def add_HILBERT_STATION_OPTIONS(opt):
+    """Add new option to the global _HILBERT_STATION_OPTIONS string of options to client-side driver"""
+    global _HILBERT_STATION_OPTIONS
+    _save = _HILBERT_STATION_OPTIONS
+
+    if _HILBERT_STATION_OPTIONS:
+        _HILBERT_STATION_OPTIONS = _HILBERT_STATION_OPTIONS + ' ' + str(opt)
+    else:
+        _HILBERT_STATION_OPTIONS = str(opt)
+
+    return _save
+
+
+def get_HILBERT_STATION_OPTIONS():
+    global _HILBERT_STATION_OPTIONS
+    return _HILBERT_STATION_OPTIONS
+
 
 ###############################################################
 def get_SSH_CONFIG():
@@ -129,6 +152,33 @@ def set_INPUT_DIRNAME(d):
     return t
 
 
+###############################################################
+def start_dry_run_mode():
+    global _DRY_RUN_MODE
+
+    if _DRY_RUN_MODE == 0:
+        _DRY_RUN_MODE = 1
+        add_HILBERT_STATION_OPTIONS('-d')
+        log.debug("DRY_RUN mode is ON! Will do remote execution in dry-mode")
+    elif _DRY_RUN_MODE == 1:
+        # NOTE: dry_run mode twice?
+        _DRY_RUN_MODE = 2
+        log.debug("DRY_RUN mode is ON+ON! No remote executions!")
+    else:
+        log.debug("NOTE: DRY_RUN mode is already ON+ON!")
+
+
+def get_DRY_RUN_MODE():
+    return _DRY_RUN_MODE
+
+
+def get_NO_REMOTE_EXEC_MODE():
+    return (get_DRY_RUN_MODE() >= 2)
+
+def get_NO_LOCAL_EXEC_MODE():
+    return (get_DRY_RUN_MODE() >= 1)
+
+
 ###############################################################
 def start_pedantic_mode():
     global PEDANTIC
@@ -195,17 +245,27 @@ def pprint(cfg):
 
 ###############################################################
 # timeout=None,
-def _execute(_cmd, shell=False, stdout=None, stderr=None):  # True??? Try several times? Overall timeout?
+def _execute(_cmd, shell=False, stdout=None, stderr=None, dry_run=False):  # True??? Try several times? Overall timeout?
+    """Same as subprocess.call but with logging and possible dry-run mode or pedantic error handling"""
+
     __cmd = ' '.join(_cmd)
     # stdout = tmp, stderr = open("/dev/null", 'w')
     # stdout=open("/dev/null", 'w'), stderr=open("/dev/null", 'w'))
     log.debug("Executing shell command: '{}'...".format(__cmd))
 
+    _shell = ''
+    if shell:
+        _shell = ' through the shell'
+
     retcode = None
     try:
         #    with subprocess.Popen(_cmd, shell=shell, stdout=stdout, stderr=stderr) as p:
         # timeout=timeout,
-        retcode = subprocess.call(_cmd, shell=shell, stdout=stdout, stderr=stderr)
+        if dry_run:
+            print("[Dry-Run-Mode] Execute [{0}]{1}".format(__cmd, _shell))
+            retcode = 0
+        else:
+            retcode = subprocess.call(_cmd, shell=shell, stdout=stdout, stderr=stderr)
     except:
         log.exception("Could not execute '{0}'! Exception: {1}".format(__cmd, sys.exc_info()))
         raise
@@ -1058,7 +1118,7 @@ def check_script(self, script):
             _cmd = ["bash", "-n", path]
             try:
                 # NOTE: Check for valid bash script
-                retcode = _execute(_cmd)
+                retcode = _execute(_cmd, dry_run=get_NO_LOCAL_EXEC_MODE())
             except:
                 log.exception("Error while running '{}' to check auto-detection script!".format(' '.join(_cmd)))
                 return False  # if PEDANTIC:  # TODO: add a special switch?
@@ -1073,7 +1133,7 @@ def check_script(self, script):
             _cmd = ["shellcheck", "-s", "bash", path]
             try:
                 # NOTE: Check for valid bash script
-                retcode = _execute(_cmd)
+                retcode = _execute(_cmd, dry_run=get_NO_LOCAL_EXEC_MODE())
             except:
                 log.exception("Error while running '{}' to check auto-detection script!".format(' '.join(_cmd)))
                 return False
@@ -1213,7 +1273,7 @@ def check(self):
             return False
 
         if PEDANTIC:
-            if not self.check_ssh_alias(_h, shell=False, timeout=2):
+            if not self.check_ssh_alias(_h, timeout=2):
                 return False
 
         return True
@@ -1228,6 +1288,9 @@ def recheck(self):
         return self.check_ssh_alias(self.get_address())
 
     def rsync(self, source, target, **kwargs):
+        if get_NO_REMOTE_EXEC_MODE():
+            kwargs['dry_run'] = True
+
         log.debug("About to rsync/ssh %s -> %s:%s...", source, str(self.get_address()), target)
         log.debug("rsync(%s, %s, %s [%s])", self, source, target, str(kwargs))
 
@@ -1266,6 +1329,9 @@ def rsync(self, source, target, **kwargs):
 
     # TODO: check/use SSH/SCP calls!
     def scp(self, source, target, **kwargs):
+        if get_NO_REMOTE_EXEC_MODE():
+            kwargs['dry_run'] = True
+
         assert self.recheck()
         _h = self.get_address()  # 'jabberwocky' #
 
@@ -1295,6 +1361,9 @@ def scp(self, source, target, **kwargs):
         return retcode
 
     def ssh(self, cmd, **kwargs):
+        if get_NO_REMOTE_EXEC_MODE():
+            kwargs['dry_run'] = True
+
         assert self.recheck()
         _h = self.get_address()  # 'jabberwocky'
 
@@ -1327,6 +1396,9 @@ def check_ssh_alias(cls, _h, **kwargs):
         """Check for ssh alias"""
         timeout = kwargs.pop('timeout', 2)
 
+        if get_NO_REMOTE_EXEC_MODE():
+            kwargs['dry_run'] = True
+
         log.debug("Checking ssh alias: '{0}'...".format(text_type(_h)))
         try:
             #            client = paramiko.SSHClient()
@@ -1518,8 +1590,6 @@ class DockerMachine(BaseRecordValidator):
     """DockerMachine :: StationPowerOnMethod"""
 
     # _DM = 'docker-machine'
-    _HILBERT_STATION = '~/bin/hilbert-station'  # TODO: look at station for this..?
-
     def __init__(self, *args, **kwargs):
         super(DockerMachine, self).__init__(*args, **kwargs)
 
@@ -1571,9 +1641,9 @@ def start(self):  # , action, action_args):
         _n = self.get_vm_name()
 
         # DISPLAY =:0
-        _cmd = [self._HILBERT_STATION, 'dm_start', _n]  # self._DM
+        _cmd = [_HILBERT_STATION, _HILBERT_STATION_OPTIONS, 'dm_start', _n]  # self._DM
         try:
-            _ret = _a.ssh(_cmd, shell=True)
+            _ret = _a.ssh(_cmd, shell=True)  # TODO: check for that shell=True!!!???
         except:
             s = "Could not power-on virtual station {0} (at {1})".format(_n, _a)
             if not PEDANTIC:
@@ -1635,7 +1705,7 @@ def start(self):  # , action, action_args):
         _cmd = [self._WOL, _MAC]  # NOTE: avoid IP for now? {"-i", _address, }
         __cmd = ' '.join(_cmd)
         try:
-            retcode = _execute(_cmd, shell=False)
+            retcode = _execute(_cmd, dry_run=get_NO_LOCAL_EXEC_MODE())
             assert retcode is not None
             if not retcode:
                 log.debug("Command ({}) execution success!".format(__cmd))
@@ -1662,7 +1732,7 @@ def start(self):  # , action, action_args):
         _cmd = [self._WOL, "-i", _address, _MAC]
         __cmd = ' '.join(_cmd)
         try:
-            retcode = _execute(_cmd, shell=False)
+            retcode = _execute(_cmd, dry_run=get_NO_LOCAL_EXEC_MODE())
             assert retcode is not None
             if not retcode:
                 log.debug("Command ({}) execution success!".format(__cmd))
@@ -1975,8 +2045,6 @@ class Station(BaseRecordValidator):  # Wrapper?
     _client_settings_tag = text_type('client_settings')
     _type_tag = text_type('type')
 
-    _HILBERT_STATION = '~/bin/hilbert-station'
-
     def __init__(self, *args, **kwargs):
         super(Station, self).__init__(*args, **kwargs)
 
@@ -2009,8 +2077,6 @@ def __init__(self, *args, **kwargs):
 
         self._compatible_applications = {}
 
-        self._HILBERT_STATION = '~/bin/hilbert-station'
-
         self._profile = None
 
     def add_application(self, app_id, app):
@@ -2059,7 +2125,7 @@ def get_profile_ref(self):
         assert _profile_id is not None
         assert _profile_id != ''
 
-        log.debug("Station's profile ID: %s", _profile_id)
+#        log.debug("Station's profile ID: %s", _profile_id)
 
         return _profile_id
 
@@ -2131,7 +2197,7 @@ def shutdown(self):
         assert isinstance(_a, HostAddress)
 
         try:
-            _ret = _a.ssh([self._HILBERT_STATION, "stop"], shell=False)
+            _ret = _a.ssh([_HILBERT_STATION, _HILBERT_STATION_OPTIONS, "stop"])
         except:
             s = "Could not stop Hilbert on the station {}".format(_a)
             if not PEDANTIC:
@@ -2145,7 +2211,7 @@ def shutdown(self):
             return False
 
         try:
-            _ret = _a.ssh([self._HILBERT_STATION, "shutdown", "now"], shell=False)
+            _ret = _a.ssh([_HILBERT_STATION, _HILBERT_STATION_OPTIONS, "shutdown", "now"])
         except:
             s = "Could not schedule immediate shutdown on the station {}".format(_a)
             if not PEDANTIC:
@@ -2160,7 +2226,7 @@ def shutdown(self):
             return False
 
         try:
-            _ret = _a.ssh([self._HILBERT_STATION, "shutdown"], shell=False)
+            _ret = _a.ssh([_HILBERT_STATION, _HILBERT_STATION_OPTIONS, "shutdown"])
         except:
             s = "Could not schedule delayed shutdown on the station {}".format(_a)
             if not PEDANTIC:
@@ -2232,7 +2298,11 @@ def deploy(self):
                 # NOTE: ATM only compose && Application/ServiceIDs == refs to the same docker-compose.yml!
                 # TODO: NOTE: may differ depending on Station::type!
 
-                tmp.write('declare -Agr services_and_applications=(\\\n')
+                # NOTE: the following variables should be set in order to generate a valid config file:
+                # hilbert_station_services_and_applications
+                # hilbert_station_profile_services
+                # hilbert_station_compatible_applications
+                tmp.write('declare -Agr hilbert_station_services_and_applications=(\\\n')
                 #               ss = []
                 for k in _serviceIDs:
                     s = all_services.get(k, None)  # TODO: check compatibility during verification!
@@ -2276,7 +2346,6 @@ def deploy(self):
                         # TODO: app.check()
 
                         app.copy(tmpdir)
-
                     else:
                         log.warning('Default application %s is not in the list of compatible apps!', app)
 
@@ -2291,10 +2360,10 @@ def deploy(self):
             # NOTE: tmp is now generated!
 
             try:
-                #            _cmd = ["scp", path, "{0}:/tmp/{1}".format(_a, os.path.basename(path))]  # self._HILBERT_STATION, 'deploy'
+                #            _cmd = ["scp", path, "{0}:/tmp/{1}".format(_a, os.path.basename(path))]  # _HILBERT_STATION, 'deploy'
                 # _a.scp(path, remote_tmpdir, shell=False)
                 log.debug("About to deploy %s -> %s... (%s)", tmpdir, remote_tmpdir, str(_a.get_address()))
-                _a.rsync(tmpdir, remote_tmpdir, shell=False)
+                _a.rsync(tmpdir, remote_tmpdir) #  , dry_run=dry_run)
             except:
                 log.debug("Exception during deployment!")
                 s = "Could not deploy new local settings to {}".format(_a)
@@ -2312,11 +2381,15 @@ def deploy(self):
         finally:
             log.debug("Temporary Station Configuration File: {}".format(path))
             os.umask(saved_umask)
-            shutil.rmtree(tmpdir)  # NOTE: tmpdir is not empty!
 
-        _cmd = [self._HILBERT_STATION, "init", remote_tmpdir]
+            if not get_NO_LOCAL_EXEC_MODE():
+                shutil.rmtree(tmpdir)  # NOTE: tmpdir is not empty!
+            else:
+                print("[Dry-Run-Mode] Keeping temporary location [{0}] that was prepared for deployment to [{1}]".format(tmpdir, str(_a.get_address())))
+
+        _cmd = [_HILBERT_STATION, _HILBERT_STATION_OPTIONS, "init", remote_tmpdir]
         try:
-            _ret = _a.ssh(_cmd, shell=False)
+            _ret = _a.ssh(_cmd)
         except:
             s = "Could not initialize the station using the new configuration file with {}".format(' '.join(_cmd))
             if not PEDANTIC:
@@ -2334,6 +2407,7 @@ def deploy(self):
             # TODO: what about other external resources? docker-compose*.yml etc...?
             # TODO: restart hilbert-station?
 
+
         #        raise NotImplementedError("Cannot deploy local configuration to this station!")
         return True
 
@@ -2344,7 +2418,7 @@ def app_change(self, app_id):
         assert isinstance(_a, HostAddress)
 
         try:
-            _ret = _a.ssh([self._HILBERT_STATION, "app_change", app_id], shell=False)
+            _ret = _a.ssh([_HILBERT_STATION, _HILBERT_STATION_OPTIONS, "app_change", app_id])
         except:
             s = "Could not change top application on the station '{0}' to '{1}'".format(_a, app_id)
             if not PEDANTIC:
@@ -2363,6 +2437,7 @@ def poweron(self):
         assert _d is not None
 
         poweron = _d.get(self._poweron_tag, None)
+
         if poweron is None:
             log.error("Missing/wrong Power-On Method configuration for this station!")
             raise Exception("Missing/wrong Power-On Method configuration for this station!")
@@ -2691,36 +2766,40 @@ def __init__(self, *args, **kwargs):
         self._types = {}
 
     def validate(self, d):
+        """String or a sequence of strings"""
+
+#        log.debug("LIST INPUT: [%s], LIST INPUT TYPE: [%s]", d, type(d))
+
         if d is None:
             d = self._default_input_data
 
         assert self._default_type is not None
         assert len(self._types) > 0
 
-        _lc = d.lc
 
         # NOTE: determine the class of items based on the version and sample data
         self._type = self._types[self._default_type]
         assert self._type is not None
 
         if (not isinstance(d, (list, dict, tuple, set))) and isinstance(d, string_types):
-            try:
+            try:  # NOTE: Test single string item:
                 _d = [self._type.parse(StringValidator.parse(d, parent=self))]
-                self.get_data(_d)
+                self.set_data(_d)
                 return True
             except:
                 pass  # Not a single string entry...
 
-        # list!?
-        _ret = True
+        # NOTE: handle a collection (sequence or mapping) of given _type:
 
         _d = []
+        _ret = True
         for idx, i in enumerate(d):  # What about a string?
             _v = None
             try:
                 _v = self._type.parse(i, parent=self)
                 _d.insert(idx, _v)  # append?
             except ConfigurationError as err:
+                _lc = d.lc
                 _value_error("[%d]" % idx, d, _lc, "Wrong item in the given sequence!")
                 pprint(err)
                 _ret = False
@@ -3145,10 +3224,16 @@ def validate(self, d):
                 _ret = False
 
             s = _stations[k]
+            assert s is not None
             assert isinstance(s, Station)
             p_ref = s.get_profile_ref()
-            assert p_ref in _profiles
+
+            if p_ref not in _profiles:
+                log.error("bad configuration: station '%s' has unknown/invalid profile specification: '%s'", k, p_ref)
+                return False
+
             p = _profiles[p_ref]
+            assert p is not None
             p.add_station(k, s)
 
             s.set_profile(p)
diff --git a/hilbert_config/subcmdparser.py b/hilbert_config/subcmdparser.py
index 939f550..895b352 100644
--- a/hilbert_config/subcmdparser.py
+++ b/hilbert_config/subcmdparser.py
@@ -313,5 +313,5 @@ def __call__(self, parser, args, values, option_string=None):
             except:
                 pass
 
-        parser.exit(0)
+        parser.exit()
         setattr(args, self.dest, values)
diff --git a/station/generate_ogl.sh b/station/generate_ogl.sh
index 8d28b70..4dda3bf 100755
--- a/station/generate_ogl.sh
+++ b/station/generate_ogl.sh
@@ -15,8 +15,9 @@ IMG="$U/${I}:${IMAGE_VERSION}" # IMG="$APP" #IMG="$U/$I:$APP"
 ID=$(docker images | awk '{ print "[" $1 ":" $2 "]" }' | sort | uniq | grep "\[${IMG}\]")
 
 if [ -z "$ID" ]; then
-  echo "ERROR: no such image '${IMG}'"
-  exit 2
+  echo "NOTE: no dummy image '${IMG}', pulling..."
+  docker pull "${IMG}" || exit $?
+#  exit 2
 fi
 
 #shift
@@ -34,8 +35,8 @@ docker rm -vf $C 1>&2 || true
 docker rmi -f --no-prune=false $D 1>&2 || true
 
 
-R="-it -a stdin -a stdout -a stderr --label is_top_app=0 --ipc=host --net=host --pid=host -v /etc/localtime:/etc/localtime:ro -v /tmp/:/tmp/:rw"
-O="--skip-startup-files --no-kill-all-on-exit --quiet --skip-runit"
+R="-it -a stdin -a stdout -a stderr --label is_top_app=0 --ipc=host --net=host -v /etc/localtime:/etc/localtime:ro -v /tmp/:/tmp/:rw"
+O="/sbin/my_init --skip-startup-files --quiet --skip-runit"
 
 ## Create $C conainer out of $IMG and run customization script in it:
 docker run $R --name $C $IMG $O -- bash -c 'customize.sh' 1>&2
@@ -61,7 +62,10 @@ rm -Rf $G 1>&2 || true
 
 ## generate target archive $G:
 # TODO: --recursion ? ADDEDFILES=/bin/true /lib/x86_64-linux-gnu/libc.so.6 /lib64/ld-linux-x86-64.so.2 /usr/lib/x86_64-linux-gnu/ ?
-docker run $R --rm $D $O -- bash -c "tar czvf $G --hard-dereference --dereference $A && chmod a+rw $G"
+docker run $R --rm $D $O -- bash -c "tar czvf $G --hard-dereference --dereference $A && chmod a+rw $G" && \
+(echo "Temporary OGL patch is in $G, copying to $PWD..."; cp "$G" .; )
 
 ## post-cleanup:
 docker rmi -f --no-prune=false $D 1>&2 || true
+
+
diff --git a/tests/data/miniGroupHilbert.yml b/tests/data/miniGroupHilbert.yml
new file mode 100644
index 0000000..cd9d8bc
--- /dev/null
+++ b/tests/data/miniGroupHilbert.yml
@@ -0,0 +1,91 @@
+Version: '0.9'
+Services:
+Profiles:
+  P1:
+    services: []
+    description: P1
+    name: P1
+    supported_types: []
+
+  P2:
+    services: []
+    description: P2
+    name: P2
+    supported_types: []
+Stations:
+  S1:
+    type: hidden
+    name: S1
+    description: S1
+    profile: P1
+    omd_tag: standalone
+    address: localhost
+    hidden: true
+
+  S2:
+    type: hidden
+    name: S1
+    description: S1
+    profile: P2
+    omd_tag: standalone
+    address: localhost
+    hidden: true
+
+Groups:
+  group_include: { include: S1 }
+  group_include_seq: { include: [S1] }
+  group_include_seq2: { include: [group_include, group_include_seq] }
+
+  group_exclude: { S1, exclude: S1 }
+  group_exclude_seq: { S1, exclude: [S1] }
+  group_exclude_seq2: { S1, exclude: [group_exclude, group_exclude_seq] }
+
+  group_intersectwith: { S1, intersect_with: S1 }
+  group_intersectwith_seq: { S1, intersect_with: [S1] }
+  group_intersectwith_seq2: { S1, intersect_with: [group_intersectwith, group_intersectwith_seq] }
+
+  group_spec: { S1, include: group_include, intersect_with: group_intersectwith, exclude: group_exclude }
+  group_spec_seq: { S1, include: [ group_include ], intersect_with: [group_intersectwith], exclude: [group_exclude] }
+  group_spec_seq2: { S1, include: [ group_include, group_include_seq ], intersect_with: [group_intersectwith, group_intersectwith_seq], exclude: [group_exclude, group_exclude_seq] }
+
+  # all the following groups are {S1, S2}
+  test_group_short_union1_12: {S1, S2}
+  test_group_short_union1_21: {S2, S1}
+  test_group_short_union2_12: {S1, P2}
+  test_group_short_union2_21: {S2, P1}
+  test_group_short_union3:    {P1, P2}
+
+  test_group_union1_12: { include: [S1, S2] }
+  test_group_union1_21: { include: [S2, S1] }
+  test_group_union2_12: { include: [S1, P2] }
+  test_group_union2_21: { include: [S2, P1] }
+  test_group_union3:    { include: [P1, P2] }
+
+  test_group_mix_union1_12: {S1, include: S2}
+  test_group_mix_union1_21: {S2, include: S1}
+  test_group_mix_union2_12: {S1, include: P2}
+  test_group_mix_union2_21: {S2, include: P1}
+  test_group_mix_union3:    {P1, include: P2}
+
+  # The following all are {S2}
+  test_group_exclude_short1: { include: [S1, S2], exclude: S1 }
+  test_group_exclude_short2: { include: [S1, S2], exclude: P1 }
+
+  test_group_exclude1: { include: [S1, S2], exclude: [S1] }
+  test_group_exclude2: { include: [S1, S2], exclude: [P1] }
+  test_group_exclude3: { include: [S1, S2], exclude: [S1, P1] }
+
+  # all the following groups are empty sets
+  test_group_short_intersect1: {include: S1, intersect_with: S2}
+  test_group_short_intersect2: {include: S2, intersect_with: S1}
+  test_group_short_intersect3: {include: S1, intersect_with: P2}
+  test_group_short_intersect4: {include: S2, intersect_with: P1}
+  test_group_short_intersect5: {include: P1, intersect_with: P2}
+
+  test_group_intersect1: {include: [S1], intersect_with: [S2]}
+  test_group_intersect2: {include: [S2], intersect_with: [S1]}
+  test_group_intersect3: {include: [S1], intersect_with: [P2]}
+  test_group_intersect4: {include: [S2], intersect_with: [P1]}
+  test_group_intersect5: {include: [P1], intersect_with: [P2]}
+
+Applications:
diff --git a/tests/data/miniGroupHilbert.yml.data.pickle b/tests/data/miniGroupHilbert.yml.data.pickle
new file mode 100644
index 0000000..cce80b4
Binary files /dev/null and b/tests/data/miniGroupHilbert.yml.data.pickle differ
diff --git a/tests/data/miniGroupHilbert.yml.pickle b/tests/data/miniGroupHilbert.yml.pickle
new file mode 100644
index 0000000..7da5c77
Binary files /dev/null and b/tests/data/miniGroupHilbert.yml.pickle differ
diff --git a/tests/data/singleHostHilbert.yml b/tests/data/singleHostHilbert.yml
index 01c5750..cfeb8e0 100644
--- a/tests/data/singleHostHilbert.yml
+++ b/tests/data/singleHostHilbert.yml
@@ -102,21 +102,21 @@ Stations:
 
 Groups:   # intersectWith is deprecated, use intersect_with instead
   all5: { station_defaults, main_server, station }    # Note: all 3 stations!
-#  none1: { include: {} }
-#  none2: {include: {all0}, intersect_with: { all1}, exclude: {all5} }
-  test1: { include: { main_server, station } }
-  test2: { main_server, include: { station } }
-  test3: { include: { main_server}, station }
+#  none1: { include: [] }
+#  none2: {include: [all0], intersect_with: [all1], exclude: [all5] }
+  test1: { include: [ main_server, station ] }
+  test2: { main_server, include: station }
+  test3: { include: main_server, station }
   all0: { all1 }
-  all1: { standalone, include: {server, simple}, std }
-  all6: { all1, intersect_with: { all5 } }
-  sub1: { all0, exclude: { std } }
-  sub2: { test1, exclude: { std } }
-  sub3: { test2, exclude: { standalone } }
-  sub11: { exclude: { std }, all0 }
-  sub22: { exclude: { std }, test1 }
-  sub33: { exclude: { standalone }, all5 }
-  test4: {all6, exclude: {simple}, intersect_with: { server, simple } }
+  all1: { standalone, include: [server, simple], std }
+  all6: { all1, intersect_with: all5 }
+  sub1: { all0, exclude: std }
+  sub2: { test1, exclude: std }
+  sub3: { test2, exclude: standalone }
+  sub11: { exclude: std, all0 }
+  sub22: { exclude: std, test1 }
+  sub33: { exclude: standalone, all5 }
+  test4: {all6, exclude: simple, intersect_with: [ server, simple ] }
 #  a: {a, b, exclude: {a, b}, intersect_with: {a, b}, include: {a, b}}
 #  b: { a}
 #  c: { exclude: {none1} }
diff --git a/tests/test_validate.py b/tests/test_validate.py
index ffca248..a61588c 100644
--- a/tests/test_validate.py
+++ b/tests/test_validate.py
@@ -116,6 +116,9 @@ def test_sample(self, capsys):
     def test_single(self, capsys):
         hilbert_validation('singleHostHilbert.yml', 'singleHostHilbert.yml.data.pickle')
 
+    def test_groups(self, capsys):
+        hilbert_validation('miniGroupHilbert.yml', 'miniGroupHilbert.yml.data.pickle')
+
     def test_non_unique_app_service_ids(self, capsys):
         test_output = None
 
diff --git a/tools/hilbert-station b/tools/hilbert-station
index c6d8234..f3f694f 100755
--- a/tools/hilbert-station
+++ b/tools/hilbert-station
@@ -43,7 +43,7 @@ declare -ir LOCKFD=99
 
 ## PRIVATE flock WRAPPER API
 function _lock()             { flock "-$1" ${LOCKFD}; }
-function _no_more_locking()  { _lock u; _lock xn && rm -f "${LOCKFILE}"; }
+function _no_more_locking()  { _lock u; _lock xn && rm -f "${LOCKFILE}"; exec 2>&4 1>&3; }
 function _prepare_locking()  { eval "exec $LOCKFD>\"$LOCKFILE\""; trap _no_more_locking EXIT; }
 
 ## PUBLIC flock WRAPPER API
@@ -152,7 +152,7 @@ fi
 ## @fn cmd_usage Show CLI usage help
 function cmd_usage() {
     cat << EOF
-usage: ${TOOL} [-h] [-p] [-V] [-v | -q] subcommand
+usage: ${TOOL} [-h] [-d|-D] [-t|-T] [-V] [-v|-q] subcommand
 
 Hilbert - client part for Linux systems
 
@@ -370,7 +370,7 @@ while getopts ":hqtTdDvV" opt; do   # NOTE: removed 'p' for now
         ;;
     d )
         DEBUG "Turning on dry-run mode..."
-        DRY_RUN="dry-run-mode"
+        DRY_RUN="Dry-Run-Mode"
         ;;
     D )
         DEBUG "Turning off dry-run mode..."
@@ -440,7 +440,7 @@ function _service_get_type() {
 
 function _service_get_field() {
     local k="$1:$2"
-    echo "${services_and_applications[$k]}"
+    echo "${hilbert_station_services_and_applications[$k]}"
     return $?
 }
 
@@ -556,18 +556,49 @@ function cmd_install_station_config() {
 ## @fn cmd_read_configuration
 function cmd_read_configuration() {
     if [[ ! -r "${HILBERT_CONFIG_FILE}" ]]; then
-        ERROR "Could not read configuration from '${HILBERT_CONFIG_FILE}'!"
+        ERROR "Configuration file '${HILBERT_CONFIG_FILE}' is not readable ($(ls -la ${HILBERT_CONFIG_FILE})!"
         exit 1
     fi
 
-    # NOTE: read station configuration:
+    # NOTE: try to read/check station configuration only once (if it is valid):
+    declare -p "hilbert_station_services_and_applications" 1>>/dev/null 2>&1
+    if [[ $? -eq 0 ]]; then
+        DEBUG "Configuration file has been loaded already!"
+        return 0
+    fi
+
+    declare -p "hilbert_station_profile_services" 1>>/dev/null 2>&1
+    if [[ $? -eq 0 ]]; then
+        DEBUG "Configuration file has been loaded already!"
+        return 0
+    fi
+
+    declare -p "hilbert_station_profile_services" 1>>/dev/null 2>&1
+    if [[ $? -eq 0 ]]; then
+        DEBUG "Configuration file has been loaded already!"
+        return 0
+    fi
+
     source "${HILBERT_CONFIG_FILE}"  # TODO: FIXME: only pass declare ... key="...value..."!?
+    local _ret=$?
 
-    if [[ -v services_and_applications ]]; then
-        ERROR "Configuration file '${HILBERT_CONFIG_FILE}' does not set 'services_and_applications'!"
+    declare -p "hilbert_station_services_and_applications" 1>>/dev/null 2>&1
+    if [[ $? -ne 0 ]]; then
+        ERROR "Wrong local configuration file: '${HILBERT_CONFIG_FILE}'! NOTE: it should set at least 'hilbert_station_services_and_applications'!"
         exit 1
     fi
-    return $?
+
+    declare -p "hilbert_station_profile_services" 1>>/dev/null 2>&1
+    if [[ $? -ne 0 ]]; then
+        DEBUG "Strange local configuration file: '${HILBERT_CONFIG_FILE}': 'hilbert_station_profile_services' is not set!"
+    fi
+
+    declare -p "hilbert_station_compatible_applications" 1>>/dev/null 2>&1
+    if [[ $? -ne 0 ]]; then
+        DEBUG "Strange local configuration file: '${HILBERT_CONFIG_FILE}': 'hilbert_station_compatible_applications' is not set!"
+    fi
+
+    return ${_ret}
 }
 
 ## @fn cmd_init
@@ -577,7 +608,7 @@ function cmd_init() {
 
     if [[ ! -w "/dev/pts/ptmx" ]]; then
         if [[ -n "${DRY_RUN}" ]]; then
-            echo "Running: [chmod a+rw /dev/pts/ptmx]..."
+            echo "[${DRY_RUN}] Running: [chmod a+rw /dev/pts/ptmx]..."
         else
             DEBUG "Trying to fix '/dev/pts/ptmx'-permissions:"
 
@@ -613,7 +644,7 @@ function cmd_init() {
     if [[ -n "${DOCKER_GC}" ]]; then
         if hash "${DOCKER_GC}" 2>/dev/null; then
             if [[ -z "${DRY_RUN}" ]]; then
-                DEBUG "Running: [${DOCKER_GC}]: "
+                echo "[${DRY_RUN}] Running: [${DOCKER_GC}]: "
 #                ${DOCKER_GC}  # NOTE: actually run this in production!
             else
                 echo "Running: [${DOCKER_GC}]"
@@ -671,6 +702,8 @@ function cmd_start_service() {
         exit 1
     fi
 
+    cmd_read_configuration
+
     local t
     t="$(_service_get_type "${arg}")"
 
@@ -703,6 +736,8 @@ function cmd_init_service() {
         exit 1
     fi
 
+    cmd_read_configuration
+
     local t
     t="$(_service_get_type "${arg}")"
 
@@ -737,6 +772,8 @@ function cmd_restart_service() {
         exit 1
     fi
 
+    cmd_read_configuration
+
     local t
     t="$(_service_get_type "${arg}")"
 
@@ -771,6 +808,8 @@ function cmd_stop_service() {
         exit 1
     fi
 
+    cmd_read_configuration
+
     local t
     t="$(_service_get_type "${arg}")"
 
@@ -797,7 +836,7 @@ function cmd_compose_start() {
     export HILBERT_APPLICATION_ID="$arg"  # NOTE: To be set as env. variable APP_ID within container...
 
     ## NOTE: Simplify COMPOSE_FILE -> launch!
-    local PLAIN_COMPOSE_FILE="${HILBERT_CONFIG_DIR}/docker-compose.plain.${HILBERT_APPLICATION_ID}.yaml"
+    local PLAIN_COMPOSE_FILE="${HILBERT_CONFIG_DIR}/cached_for_${HILBERT_APPLICATION_ID}.${HILBERT_APPLICATION_FILE:-docker-compose.yml}"
     if [[ -r ${PLAIN_COMPOSE_FILE} ]]; then
         export COMPOSE_FILE="${PLAIN_COMPOSE_FILE}"
     else
@@ -827,7 +866,7 @@ function cmd_compose_init() {
     export COMPOSE_FILE="${HILBERT_APPLICATION_FILE:-docker-compose.yml}"  # Default value
     export HILBERT_APPLICATION_ID="$arg"  # NOTE: To be set as env. variable APP_ID within container...
 
-    local PLAIN_COMPOSE_FILE="${HILBERT_CONFIG_DIR}/docker-compose.plain.${HILBERT_APPLICATION_ID}.yaml"
+    local PLAIN_COMPOSE_FILE="${HILBERT_CONFIG_DIR}/cached_for_${HILBERT_APPLICATION_ID}.${HILBERT_APPLICATION_FILE:-docker-compose.yml}"
     DEBUG "Trying to simplify: '${COMPOSE_FILE}' -> '${PLAIN_COMPOSE_FILE}': "
     cmd_docker_compose config > "${PLAIN_COMPOSE_FILE}"
     ## NOTE: running config once should be enough... ?
@@ -863,7 +902,7 @@ function cmd_compose_restart() {
     export HILBERT_APPLICATION_ID="$arg"  # NOTE: To be set as env. variable APP_ID within container...
 
     ## NOTE: Simplify COMPOSE_FILE -> launch!
-    local PLAIN_COMPOSE_FILE="${HILBERT_CONFIG_DIR}/docker-compose.plain.${HILBERT_APPLICATION_ID}.yaml"
+    local PLAIN_COMPOSE_FILE="${HILBERT_CONFIG_DIR}/cached_for_${HILBERT_APPLICATION_ID}.${HILBERT_APPLICATION_FILE:-docker-compose.yml}"
     if [[ -r ${PLAIN_COMPOSE_FILE} ]]; then
         export COMPOSE_FILE="${PLAIN_COMPOSE_FILE}"
     else
@@ -890,7 +929,7 @@ function cmd_compose_stop() {
     export HILBERT_APPLICATION_ID="$arg"  # NOTE: To be set as env. variable APP_ID within container...
 
     ## NOTE: Simplify COMPOSE_FILE -> launch!
-    local PLAIN_COMPOSE_FILE="${HILBERT_CONFIG_DIR}/docker-compose.plain.${HILBERT_APPLICATION_ID}.yaml"
+    local PLAIN_COMPOSE_FILE="${HILBERT_CONFIG_DIR}/cached_for_${HILBERT_APPLICATION_ID}.${HILBERT_APPLICATION_FILE:-docker-compose.yml}"
     if [[ -r ${PLAIN_COMPOSE_FILE} ]]; then
         export COMPOSE_FILE="${PLAIN_COMPOSE_FILE}"
     else
@@ -931,7 +970,7 @@ function cmd_docker_stop() {
 
 function cmd_docker_compose() {
     if [[ -n "${DRY_RUN}" ]]; then
-        echo "Running: [${DOCKER_COMPOSE} --skip-hostname-check $*]"
+        echo "[${DRY_RUN}] Running: [${DOCKER_COMPOSE} --skip-hostname-check $*]"
         return 0
     fi
 
@@ -975,7 +1014,7 @@ function cmd_docker_compose() {
 
 function cmd_docker() {
     if [[ -n "${DRY_RUN}" ]]; then
-        echo "Running: [${DOCKER} $*]"
+        echo "[${DRY_RUN}] Running: [${DOCKER} $*]"
         return 0
     fi
 
@@ -1310,7 +1349,12 @@ function cmd_stop() {
 function cmd_shutdown() {
     local arg=$@
     DEBUG "Shutting this system down... Arguments: [${arg}]"
-    ${SHUTDOWN} ${arg} || sudo -n -P ${SHUTDOWN} ${arg}
+
+    if [[ -n "${DRY_RUN}" ]]; then
+        echo "[${DRY_RUN}] Running: [${SHUTDOWN} ${arg} || sudo -n -P ${SHUTDOWN} ${arg}]..."
+    else
+        ${SHUTDOWN} ${arg} || sudo -n -P ${SHUTDOWN} ${arg}
+    fi
 }
 
 ## @fn cmd_subcommand_handle Main CLI parser/handler
diff --git a/tools/hilbert.py b/tools/hilbert.py
index e16b288..e842626 100755
--- a/tools/hilbert.py
+++ b/tools/hilbert.py
@@ -56,6 +56,24 @@
 #    log.exception("Uncaught exception! Type: {0}, Value: {1}, TB: {2}".format(type, value, traceback.format_tb(tb)))
 ##sys.excepthook = main_exception_handler # Install exception handler
 
+
+def set_log_level_options(_ctx):
+    if 'verbose' in _ctx:
+        c = _ctx['verbose']
+        if c is None:
+            c = 0
+        for i in range(c):
+            add_HILBERT_STATION_OPTIONS('-v')
+
+    if 'quiet' in _ctx:
+        c = _ctx['quiet']
+        if c is None:
+            c = 0
+        for i in range(c):
+            add_HILBERT_STATION_OPTIONS('-q')
+
+
+
 @subcmd('cfg_verify', help='verify the correctness of Hilbert Configuration .YAML file')
 def cmd_verify(parser, context, args):
     log.debug("Running '{}'".format('cfg_verify'))
@@ -66,9 +84,12 @@ def cmd_verify(parser, context, args):
     args = parser.parse_args(args)
     cfg = input_handler(parser, vars(context), args)
 
-    assert cfg is not None
+    if cfg is not None:
+        print("Input is a valid Hilbert configuration!")
+    else:
+        print("Input seems to be invalid Hilbert configuration!")
+        sys.exit(1)
 
-    log.debug("Done")
     return args
 
 
@@ -96,8 +117,6 @@ def input_handler(parser, ctx, args):
             fn = os.path.join('.', 'Hilbert.yml')
             log.info("Missing input file specification: using default: '{}'!".format(fn))
 
-
-
     if (fn is not None) and (df is not None):
         log.error("Input file specification clashes with the input dump specification: specify a single input source!")
         sys.exit(1)
@@ -228,7 +247,6 @@ def cmd_query(parser, context, args):
         log.info("Writing the configuration into '{}'...".format(od))
         pickle_dump(od, obj)
 
-    log.debug("Done")
     return args
 
 
@@ -261,7 +279,6 @@ def cmd_list_applications(parser, context, args):
     else:
         print(yaml_dump(obj))
 
-    log.debug("Done")
     return args
 
 
@@ -368,7 +385,6 @@ def cmd_list_stations(parser, context, args):
 
         print(']')
 
-    log.debug("Done")
     return args
 
 
@@ -401,7 +417,6 @@ def cmd_list_profiles(parser, context, args):
     else:
         print(yaml_dump(obj))
 
-    log.debug("Done")
     return args
 
 
@@ -434,7 +449,6 @@ def cmd_list_groups(parser, context, args):
     else:
         print(yaml_dump(obj))
 
-    log.debug("Done")
     return args
 
 
@@ -467,14 +481,13 @@ def cmd_list_services(parser, context, args):
     else:
         print(yaml_dump(obj))
 
-    log.debug("Done")
     return args
 
-
 # NOTE: just a helper ATM
 def cmd_action(parser, context, args, Action=None, appIdRequired=False):
     args = parser.parse_args(args)
     _args = vars(args)
+    _ctx = vars(context)
 
     action = Action
     if action is None:
@@ -506,6 +519,7 @@ def cmd_action(parser, context, args, Action=None, appIdRequired=False):
     elif 'action_args' in _args:
         action_args = _args.get('action_args', None)
 
+
     stations = None
     log.debug("Validating given StationID: '%s'...", stationId)
     try:
@@ -519,6 +533,7 @@ def cmd_action(parser, context, args, Action=None, appIdRequired=False):
 
     if stationId not in stations.get_data():
         log.error("Invalid StationID (%s)!", stationId)
+        print()
         sys.exit(1)
 
     station = stations.get_data()[stationId]
@@ -526,6 +541,9 @@ def cmd_action(parser, context, args, Action=None, appIdRequired=False):
 
     log.debug("StationID is valid according to the Configuration!")
     log.debug("Running action: '{0} {1}' on station '{2}'".format(action, str(action_args), stationId))
+
+    set_log_level_options(_ctx)
+
     try:
         station.run_action(action, action_args)  # NOTE: temporary API for now
     except:
@@ -551,7 +569,6 @@ def cmd_start(parser, context, args):
 
     cmd_action(parser, context, args, Action=action, appIdRequired=False)
 
-    log.debug("Done")
     return args
 
 
@@ -572,7 +589,6 @@ def cmd_stop(parser, context, args):
 
     cmd_action(parser, context, args, Action=action, appIdRequired=False)
 
-    log.debug("Done")
     return args
 
 
@@ -593,7 +609,6 @@ def cmd_cfg_deploy(parser, context, args):
 
     cmd_action(parser, context, args, Action=action, appIdRequired=False)
 
-    log.debug("Done")
     return args
 
 
@@ -615,7 +630,6 @@ def cmd_app_start(parser, context, args):
 
     cmd_action(parser, context, args, Action=action, appIdRequired=True)
 
-    log.debug("Done")
     return args
 
 
@@ -638,7 +652,6 @@ def cmd_app_stop(parser, context, args):
 
     cmd_action(parser, context, args, Action=action, appIdRequired=True)
 
-    log.debug("Done")
     return args
 
 
@@ -660,7 +673,6 @@ def cmd_app_change(parser, context, args):
 
     cmd_action(parser, context, args, Action=action, appIdRequired=True)
 
-    log.debug("Done")
     return args
 
 
@@ -680,7 +692,6 @@ def cmd_run_action(parser, context, args):
 
     cmd_action(parser, context, args, Action=None, appIdRequired=False)
 
-    log.debug("Done")
     return args
 
 
@@ -693,6 +704,26 @@ def __call__(self, *args, **kwargs):
         start_pedantic_mode()
 
 
+class RemoteTraceModeAction(argparse._StoreTrueAction):
+    def __init__(self, *args, **kwargs):
+        super(RemoteTraceModeAction, self).__init__(*args, **kwargs)
+
+    def __call__(self, *args, **kwargs):
+        super(RemoteTraceModeAction, self).__call__(*args, **kwargs)
+        add_HILBERT_STATION_OPTIONS('-t')
+
+
+class CountedDryRunModeAction(argparse._CountAction):
+    def __init__(self, *args, **kwargs):
+        super(CountedDryRunModeAction, self).__init__(*args, **kwargs)
+
+    def __call__(self, parser, namespace, values, option_string=None):
+        new_count = argparse._ensure_value(namespace, self.dest, 0) + 1
+        setattr(namespace, self.dest, new_count)
+
+        start_dry_run_mode()  # increase
+
+
 def _version():
     import platform
     import dill
@@ -707,10 +738,11 @@ def _version():
     log.debug("logging           version: {}".format(logging.__version__))
     log.debug("semantic_version  version: {}".format(semantic_version.__version__))
 
-
     print("Hilbert Configuration API:     {}".format(Hilbert(None).get_api_version()))
     print("Root Logging Level:            {}".format(logging.getLevelName(logging.getLogger().level)))
     print("PEDANTIC mode:                 {}".format(get_PEDANTIC()))
+    print("DRY_RUN mode:                  {}".format(get_DRY_RUN_MODE()))
+    print("HILBERT_STATION_OPTIONS:       {}".format(get_HILBERT_STATION_OPTIONS()))
 
     d = os.environ.get('HILBERT_SERVER_CONFIG_PATH', None)
     if d is not None:
@@ -720,21 +752,21 @@ def _version():
     if d is not None:
         print("HILBERT_SERVER_CONFIG_SSH_PATH:  {}".format(d))
 
-#    print("INPUT_DIRNAME:                 {}".format(get_INPUT_DIRNAME()))
-    log.debug("Done")
+
+# print("INPUT_DIRNAME:                 {}".format(get_INPUT_DIRNAME()))
 
 
-class ListVersionsAction(argparse.Action):
+class ListVersionsAction(argparse._VersionAction):
     def __init__(self, option_strings, *args, **kwargs):
         super(ListVersionsAction, self).__init__(option_strings=option_strings, *args, **kwargs)
 
     def __call__(self, parser, args, values, option_string=None):
+        set_log_level_options(vars(args))
+#        formatter = parser._get_formatter()
+#        formatter.add_text(version)
+#        parser._print_message(formatter.format_help(), _sys.stdout)
         _version()
-        parser.exit(status=0)
-
-
-# setattr(args, self.dest, values)
-
+        parser.exit()
 
 def main():
     handler = SubCommandHandler(use_subcommand_help=True, enable_autocompletion=True,
@@ -745,9 +777,17 @@ def main():
                          default=argparse.SUPPRESS, required=False,
                          help="turn on pedantic mode")
 
+    handler.add_argument('-t', '--trace', action=RemoteTraceModeAction,
+                         default=argparse.SUPPRESS, required=False,
+                         help="turn on remote verbose-trace mode")
+
+    handler.add_argument('-d', '--dryrun', action=CountedDryRunModeAction,
+                         help="increase dry-run mode")
+
     handler.add_argument('-V', '--version', action=ListVersionsAction,
-                         nargs=0, default=argparse.SUPPRESS, required=False, type=None, metavar=None,
                          help="show %(prog)s's version and exit")
+    #              nargs=0, default=argparse.SUPPRESS, required=False, type=None, metavar=None,
+
 
     _argv = sys.argv[1:]
 
@@ -755,10 +795,11 @@ def main():
     if len(_argv) == 0:
         log.debug("No command arguments given => Showing usage help!")
         _argv = ['-h']
-    #        handler.print_help()
+    # handler.print_help()
 
     args = handler.run(_argv)
-    handler.exit(status=0)
+    handler.exit()
+
 
 if __name__ == "__main__":
     main()