diff --git a/core/addAndCheckGitRepository.sh b/core/addAndCheckGitRepository.sh
index 2368f02..f9bb8b2 100755
--- a/core/addAndCheckGitRepository.sh
+++ b/core/addAndCheckGitRepository.sh
@@ -99,9 +99,9 @@ function addAndCheckGitRepository() {
 }
 
 # sanitizes all parameters
-base.set FOLDER "${1}" '^[-a-zA-Z0-9/:@._]*/$' || exit 1
-base.set RIGHTS "${2}" '^(readonly|writable)$' || exit 1
-base.set SUGGESTED_REPOSITORY "${3}" '^([-a-zA-Z0-9/:@._]*)?$' || exit 1
+base.set FOLDER "${1}" '^[-a-zA-Z0-9/:@._]*/$'
+base.set RIGHTS "${2}" '^(readonly|writable)$'
+base.set SUGGESTED_REPOSITORY "${3}" '^[-a-zA-Z0-9/:@._]*$' optional
 addAndCheckGitRepository \
     "${FOLDER:?"Missing FOLDER"}" \
     "${RIGHTS:?"Missing RIGHTS"}" \
diff --git a/core/addNormalUser.sh b/core/addNormalUser.sh
index e625cbf..6dd89e2 100755
--- a/core/addNormalUser.sh
+++ b/core/addNormalUser.sh
@@ -37,7 +37,7 @@ function addNormalUser() {
 }
 
 # sanitizes all parameters
-base.set USER "${1}" '^[a-z][-a-z0-9_.]*$' || exit 1
+base.set USER "${1}" '^[a-z][-a-z0-9_.]*$'
 addNormalUser "${USER:?"Missing USER"}" \
     && exit 0
 
diff --git a/core/addToCrontabEveryHour.sh b/core/addToCrontabEveryHour.sh
index 567a2b2..769e864 100755
--- a/core/addToCrontabEveryHour.sh
+++ b/core/addToCrontabEveryHour.sh
@@ -44,8 +44,8 @@ function addToCrontabEveryHour() {
 }
 
 # sanitizes all parameters
-base.set COMMAND "${1}" '^[-a-zA-Z0-9/:@._]*$' || exit 1
-base.set MINUTE_VALUE "${2}" '^[-a-zA-Z0-9/:@._]*$' || exit 1
+base.set COMMAND "${1}" '^[-a-zA-Z0-9/:@._]*$'
+base.set MINUTE_VALUE "${2}" '^[-a-zA-Z0-9/:@._]*$'
 addToCrontabEveryHour \
     "${COMMAND:?"Missing COMMAND"}" \
     "${MINUTE_VALUE:?"Missing MINUTE_VALUE"}" \
diff --git a/core/base.module.sh b/core/base.module.sh
index 1f3e5ae..593bce9 100755
--- a/core/base.module.sh
+++ b/core/base.module.sh
@@ -290,7 +290,7 @@ function base.loadModule() {
 
 function base.log() {
     local _LOGLEVEL _LOGLEVEL_UPPER
-    base.set _LOGLEVEL "${1}" '^(error|warn|info|debug)$' || exit 1
+    base.set _LOGLEVEL "${1}" '^(error|warn|info|debug)$'
     _LOGLEVEL_UPPER="${_LOGLEVEL:?"base.log(): Missing valid first parameter LOGLEVEL"}"
     _LOGLEVEL_UPPER="${_LOGLEVEL_UPPER^^}"
     readonly _LOGLEVEL_UPPER
diff --git a/core/defineAuthorizedKeysOfUser.sh b/core/defineAuthorizedKeysOfUser.sh
index d9e4582..03f5553 100755
--- a/core/defineAuthorizedKeysOfUser.sh
+++ b/core/defineAuthorizedKeysOfUser.sh
@@ -136,8 +136,8 @@ function defineAuthorizedKeysOfUser() {
 }
 
 # sanitizes all parameters
-base.set DEFINITIONS "${1}" '^[-a-zA-Z0-9/:@._]*$' || exit 1
-base.set USER "${2}" '^[-a-zA-Z0-9/:@._]*$' || exit 1
+base.set DEFINITIONS "${1}" '^[-a-zA-Z0-9/:@._]*$'
+base.set USER "${2}" '^[-a-zA-Z0-9/:@._]*$'
 defineAuthorizedKeysOfUser \
     "${DEFINITIONS:?"Missing DEFINITIONS"}" \
     "${USER:?"Missing USER"}" \
diff --git a/core/ensureUsageOfDefinitions.sh b/core/ensureUsageOfDefinitions.sh
index 2d7e512..ac00385 100755
--- a/core/ensureUsageOfDefinitions.sh
+++ b/core/ensureUsageOfDefinitions.sh
@@ -218,8 +218,8 @@ function ensureUsageOfDefinitions() {
 }
 
 # sanitizes all parameters
-base.set DEFINITIONS "${1}" '^[-a-zA-Z0-9/:@._]*$' || exit 1
-base.set CURRENT_FULLFILE "${2}" '^[-a-zA-Z0-9/:@._]*$' || exit 1
+base.set DEFINITIONS "${1}" '^[-a-zA-Z0-9/:@._]*$'
+base.set CURRENT_FULLFILE "${2}" '^[-a-zA-Z0-9/:@._]*$'
 ensureUsageOfDefinitions \
     "${DEFINITIONS:?"Missing DEFINITIONS"}" \
     "${CURRENT_FULLFILE:?"Missing CURRENT_FULLFILE"}" \
diff --git a/script/host/zfs/composition-sync/setupSyncHost.sh b/script/host/zfs/composition-sync/setupSyncHost.sh
index 1c04622..f694238 100755
--- a/script/host/zfs/composition-sync/setupSyncHost.sh
+++ b/script/host/zfs/composition-sync/setupSyncHost.sh
@@ -50,7 +50,7 @@ function setup() {
 
 
 
-base.set COMPOSITION "${1}" '^([a-zA-Z0-9][a-zA-Z0-9_-]*)?$' || exit 1
+base.set COMPOSITION "${1}" '^[a-zA-Z0-9][a-zA-Z0-9_-]*$' optional
 setup "${COMPOSITION}"
 
 
diff --git a/script/host/zfs/composition-sync/sync-send.sh b/script/host/zfs/composition-sync/sync-send.sh
index 09bfe8b..9ec690a 100755
--- a/script/host/zfs/composition-sync/sync-send.sh
+++ b/script/host/zfs/composition-sync/sync-send.sh
@@ -130,11 +130,11 @@ function send() {
 # Parameter 3: Only alphanumeric characters allowed and [.-]   if not leading (due to: -oProxyCommand=...).
 # Parameter 4: Only alphanumeric characters allowed and [._:-] if not leading (due to: -oProxyCommand=...), but can be empty.
 # Parameter 5: Only alphanumeric characters allowed and [._:-] if not leading (due to: -oProxyCommand=...), but can be empty.
-base.set RECEIVERHOST "${1}" '^[a-zA-Z0-9][a-zA-Z0-9._-]*$' || exit 1
-base.set ZFS_BRANCH "${2}" '^[a-zA-Z][a-zA-Z0-9/_-]*[a-zA-Z0-9]$' || exit 1
-base.set COMPOSITION "${3}" '^[a-zA-Z0-9][a-zA-Z0-9.-]*$' || exit 1
-base.set RECEIVERS_SNAPSHOT "${4}" '(^[a-zA-Z0-9][a-zA-Z0-9._:-]*$)?' || exit 1
-base.set RESUME_TOKEN "${5}" '(^[a-zA-Z0-9][a-zA-Z0-9._:-]*$)?' || exit 1
+base.set RECEIVERHOST "${1}" '^[a-zA-Z0-9][a-zA-Z0-9._-]*$'
+base.set ZFS_BRANCH "${2}" '^[a-zA-Z][a-zA-Z0-9/_-]*[a-zA-Z0-9]$'
+base.set COMPOSITION "${3}" '^[a-zA-Z0-9][a-zA-Z0-9.-]*$'
+base.set RECEIVERS_SNAPSHOT "${4}" '^[a-zA-Z0-9][a-zA-Z0-9._:-]*$' optional
+base.set RESUME_TOKEN "${5}" '^[a-zA-Z0-9][a-zA-Z0-9._:-]*$' optional
 
 # Resume mode
 if [ "${RECEIVERS_SNAPSHOT}" == "RESUME" ]; then
diff --git a/script/host/zfs/composition-sync/sync.sh b/script/host/zfs/composition-sync/sync.sh
index c38a7ef..a9c31c8 100755
--- a/script/host/zfs/composition-sync/sync.sh
+++ b/script/host/zfs/composition-sync/sync.sh
@@ -223,8 +223,8 @@ function usage() {
 
 
 
-# Parameter 2: is optional '()?' and only a subset of alphanumeric characters are allowed and [_-] if not leading (due to: -oProxyCommand=...).
-base.set COMPOSITION "${2}" '^([a-zA-Z0-9][a-zA-Z0-9_-]*)?$'
+# Parameter 2: only a subset of alphanumeric characters are allowed and [_-] if not leading (due to: -oProxyCommand=...).
+base.set COMPOSITION "${2}" '^[a-zA-Z0-9][a-zA-Z0-9_-]*$' optional
 
 case "${1}" in
     --onceAll)
diff --git a/script/host/zfs/snapshot.sh b/script/host/zfs/snapshot.sh
index 9c6156d..33d4848 100755
--- a/script/host/zfs/snapshot.sh
+++ b/script/host/zfs/snapshot.sh
@@ -136,7 +136,7 @@ function snapshot() {
 
 
 # Parameter 1: Only one of these values (MINUTELY, HOURLY, DAILY, MONTHLY, NONE) are allowed, or empty.
-base.set MODE "${1}" '^(MINUTELY|HOURLY|DAILY|MONTHLY|NONE)?$' || exit 1
+base.set MODE "${1}" '^(MINUTELY|HOURLY|DAILY|MONTHLY|NONE)$' optional
 
 snapshot "${MODE}"
 cleanup
diff --git a/script/monitor/generic/CIS_OWN_DOMAIN_CHECK.sh b/script/monitor/generic/CIS_OWN_DOMAIN_CHECK.sh
index 59a7ba3..ffd2caf 100755
--- a/script/monitor/generic/CIS_OWN_DOMAIN_CHECK.sh
+++ b/script/monitor/generic/CIS_OWN_DOMAIN_CHECK.sh
@@ -29,6 +29,6 @@ function testDomain() {
 }
 
 # FQDN of server: e.g. host.example.net[:port]
-base.set REMOTE_HOST "${1}" '^(([a-zA-Z0-9][a-zA-Z0-9.-]*)+(:[0-9]+)?)?$'
+base.set REMOTE_HOST "${1}" '^([a-zA-Z0-9][a-zA-Z0-9.-]*)+(:[0-9]+)?$' optional
 testDomain "${REMOTE_HOST}" && exit 0
 exit 1
diff --git a/script/monitor/generic/COMPOSITION_SYNC_CHECK.sh b/script/monitor/generic/COMPOSITION_SYNC_CHECK.sh
index 01a8a58..17b91a9 100755
--- a/script/monitor/generic/COMPOSITION_SYNC_CHECK.sh
+++ b/script/monitor/generic/COMPOSITION_SYNC_CHECK.sh
@@ -75,7 +75,7 @@ function checkSync() {
 }
 
 base.set REMOTE_HOST "${1:?"FQDN of server missing: e.g. host.example.net[:port]"}" '^([a-zA-Z0-9][a-zA-Z0-9.-]*)+(:[0-9]+)?$'
-base.set GIVEN_REMOTE_HOSTNAME_FQDN "${2}" '^([a-zA-Z0-9][a-zA-Z0-9.-]*)?$'
+base.set GIVEN_REMOTE_HOSTNAME_FQDN "${2}" '^[a-zA-Z0-9][a-zA-Z0-9.-]*$' optional
 base.set MODE "${3:-"normal"}" '^(debug|normal)$'
 
 RESULTS=$(checkSync "${REMOTE_HOST}" "${MODE}" "${GIVEN_REMOTE_HOSTNAME_FQDN}")
diff --git a/script/monitor/generic/ZFS_SYNC_CHECK.sh b/script/monitor/generic/ZFS_SYNC_CHECK.sh
index f8649a0..d75a2a3 100755
--- a/script/monitor/generic/ZFS_SYNC_CHECK.sh
+++ b/script/monitor/generic/ZFS_SYNC_CHECK.sh
@@ -75,7 +75,7 @@ function checkSync() {
 }
 
 base.set REMOTE_HOST "${1:?"FQDN of server missing: e.g. host.example.net[:port]"}" '^([a-zA-Z0-9][a-zA-Z0-9.-]*)+(:[0-9]+)?$'
-base.set GIVEN_REMOTE_HOSTNAME_FQDN "${2}" '^([a-zA-Z0-9][a-zA-Z0-9.-]*)?$'
+base.set GIVEN_REMOTE_HOSTNAME_FQDN "${2}" '^[a-zA-Z0-9][a-zA-Z0-9.-]*$' optional
 base.set MODE "${3:-"normal"}" '^(debug|normal)$'
 
 RESULTS=$(checkSync "${REMOTE_HOST}" "${MODE}" "${GIVEN_REMOTE_HOSTNAME_FQDN}")
diff --git a/setupCoreOntoThisHost.sh b/setupCoreOntoThisHost.sh
index 738f691..e3f9322 100755
--- a/setupCoreOntoThisHost.sh
+++ b/setupCoreOntoThisHost.sh
@@ -208,8 +208,8 @@ function setup() {
 
 
 
-# Parameter 1: is optional '()?' and only alphanumeric characters are allowed and [.-] if not leading (due to: -oProxyCommand=...).
-base.set DOMAIN "${1}" '^([a-zA-Z0-9][a-zA-Z0-9.-]*)?$' || exit 1
+# Parameter 1: only alphanumeric characters are allowed and [.-] if not leading (due to: -oProxyCommand=...).
+base.set DOMAIN "${1}" '^[a-zA-Z0-9][a-zA-Z0-9.-]*$' optional
 setup "${DOMAIN}" \
     && exit 0
 
diff --git a/updateRepositories.sh b/updateRepositories.sh
index d8fdd37..29bf00f 100755
--- a/updateRepositories.sh
+++ b/updateRepositories.sh
@@ -73,7 +73,7 @@ function update_repositories() {
 
 
 # Parameter 1: Only one of these values are allowed, or empty (--core, --definitions, --repair, --scripts, --states, --test)?
-base.set MODE "${1}" '^(--core|--definitions|--repair|--scripts|--states|--test)?$' || exit 1
+base.set MODE "${1}" '^(--core|--definitions|--repair|--scripts|--states|--test)$' optional
 update_repositories "${MODE}" \
     && exit 0