diff --git a/about b/about
index fb90d58ba4587fa786dc0136074ec976dfcb75c0..44fb6f5d8568d0ff55821d08f04cd197460525ac 100755
--- a/about
+++ b/about
@@ -5,11 +5,14 @@
 # ABOUT
 #
 # ----------------------------------------------------------------------
-# 2020-10-23  v1.0  <axel.hahn@iml.unibe.ch>  initial version
-# 2020-10-25  v1.1  <axel.hahn@iml.unibe.ch>  show disks, show installed versions (WIP)
+# 2023-10-23  v1.0  <axel.hahn@unibe.ch>  initial version
+# 2023-10-25  v1.1  <axel.hahn@unibe.ch>  show disks, show installed versions (WIP)
+# 2023-12-22  v1.2  <axel.hahn@unibe.ch>  show help
 # ======================================================================
 
-. $( dirname $0 )/inc_pluginfunctions
+. $(dirname $0)/inc_pluginfunctions
+
+export self_APPVERSION=1.2
 
 . /etc/icingaclient/client.cfg 2>/dev/null
 
@@ -22,6 +25,32 @@
 # FUNCTIONS
 # ----------------------------------------------------------------------
 
+# show help text
+function showHelp(){
+    local _self; _self=$(basename $0)
+cat <<EOF
+$( ph.showImlHelpHeader )
+
+About ... shows a short summary for the system:
+
+  * operating system
+  * cpu
+  * ram
+  * diskspace
+  * checked services
+
+SYNTAX:
+
+  $_self [-h]
+
+OPTIONS:
+
+  -h, --help 
+      this help
+
+EOF
+}
+
 function _section(){
     echo ">>>>>>>>>> $*"
 }
@@ -30,6 +59,13 @@ function _section(){
 # MAIN
 # ----------------------------------------------------------------------
 
+# --- check param -h
+
+while [[ "$#" -gt 0 ]]; do case $1 in
+    -h|--help)      showHelp; exit 0;;
+    *) echo "ERROR: Unknown parameter: $1"; showHelp; exit 1;
+esac; done
+
 _iCpu=$( grep -c "processor" /proc/cpuinfo )
 _sCpuModel=$(grep "model name" /proc/cpuinfo | sort -u )
 _iMem=$( grep "MemTotal:"   /proc/meminfo | awk '{ print $2 }' )
diff --git a/docs/20_Checks/_index.md b/docs/20_Checks/_index.md
index 04adc02e6e43d8929d8c594dc1a4529b2139206b..c086de890b1fe51b92204b0326ee62c34832a428 100644
--- a/docs/20_Checks/_index.md
+++ b/docs/20_Checks/_index.md
@@ -7,6 +7,7 @@ There is one include script used by all checks:
 
 ## Check scripts
 
+* [about](about.md)
 * [check_apache_requests](check_apache_requests.md)
 * [check_ceph_diskfree](check_ceph_diskfree.md)
 * [check_ceph_io](check_ceph_io.md)
diff --git a/docs/20_Checks/about.md b/docs/20_Checks/about.md
new file mode 100644
index 0000000000000000000000000000000000000000..4012e25234fee2cc7a83ee0e0e5d7d2e14c23d7f
--- /dev/null
+++ b/docs/20_Checks/about.md
@@ -0,0 +1,74 @@
+# About
+
+## Introduction
+
+This check shows a short summary for the current system.
+Its status is always OK.
+
+## Requirements
+
+Nothing special.
+
+## Syntax
+
+```txt
+______________________________________________________________________
+
+ABOUT
+v1.2
+
+(c) Institute for Medical Education - University of Bern
+Licence: GNU GPL 3
+
+https://os-docs.iml.unibe.ch/icinga-checks/Checks/about.html
+______________________________________________________________________
+
+About ... shows a short summary for the system:
+
+  * perating system
+  * cpu
+  * ram
+  * diskspace
+  * checked services
+
+SYNTAX:
+
+  about [-h]
+
+OPTIONS:
+
+  -h, --help 
+      this help
+
+```
+
+## Example
+
+```txt
+# ./about
+debian 12 / 16 cpu / 62.684 GB ram
+
+>>>>>>>>>> CPU: 16
+model name      : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz
+
+>>>>>>>>>> Memory
+RAM total    65729512 kB
+Swap         999420 kB
+
+>>>>>>>>>> Disks
+Filesystem                       Size  Used Avail Use% Mounted on
+/dev/mapper/icinga--01--vg-root  218G   28G  179G  14% /
+/dev/sda1                        455M  105M  326M  25% /boot
+
+>>>>>>>>>> Services
+Apache-httpd
+Carbon-Cache
+Cron
+Cronjob-watcher
+Icinga2
+Icinga-Director
+Mariadb
+PHP-FPM
+Postfix
+SSH
+```