diff --git a/README.md b/README.md
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--- a/README.md
+++ b/README.md
@@ -14,25 +14,37 @@ It is also possible to use (by default enabled in the YSFReflector.ini) a callsi
 
 The result of this check can be overdriven by a whitelist-entry in the blocklist (for example: N0CALL is blocked by default by this expression but could be allowed for special bridging situations).
 
+### Muting Matrix
+Here you see a matrix documenting the behavior of the blocking-lists and configuration of regular expression (RE)-check:
+
+![Muting-Matrix](img/Muting-Matrix.png "Muting-Matrix")
+
+Within this table following descriptions for the cell-values should help understanding the table:
+* X: Any value
+* YES: set and matches with callsign/gateway/ip-address	
+* NO: not set	
+* 1: check via RE enabled, normal operation	
+* 0: check via RE disabled, but passes everything	
+* -1: check via RE disabled, but only pass whitelist	
+
 ### Avoiding Parallel Incomming Transmissions
 There is also a functionality implemented that prohibits parallel transmissions that can happen if two senders transmit at the same time. Here the principle 'first-comes-first-serves' is realized, so the second station in time will just be muted to not disturb the audio.
 
 ## Easy Installation And Upgrade
 Depending on your used operating system and python3-installation you just have to take care that following libraries are installed:
 
-* socket
-* threading
-* queue
-* sys
-* os
-* time
-* re
+* bisect
 * configparser
 * datetime
+* os
+* queue
+* re
 * signal
-* datetime
-* bisect
+* socket
 * struct
+* sys
+* threading
+* time
 
 In most installations this packages are already installed, otherwise you easily can install them with your system-package-manager (for example Debian: apt) or you use pip3 install <package>-command.
 
diff --git a/documentation/API.md b/documentation/API.md
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@@ -0,0 +1,81 @@
+# API-Call Documentation
+## Introduction
+As many of us know YSFReflectors use the YSF protocol to communicate with endpoints. These original commands are well 
+documented at http://ycs-wiki.xreflector.net/doku.php?id=start:protocols:ysf  thanks to the YCS-team for hosting them.
+pYSFReflector has also an extended set of commands you can use for fetching information on the state of different things 
+when running the reflector.
+
+This document will show the commands, and the replies expected from the reflector.
+
+## How To Issue A Call
+First it is very easy to have a command sent to a reflector. Simply use a command similar to this:
+
+`echo -n "YSFS" | nc -u 127.0.0.1 42000 -w 2 && echo`
+
+or in a more general form:
+
+`echo -n "<COMMAND>" | nc -u <IP-ADDRESS_OF_REFLECTOR> <PORT_OF_REFLECTOR> -w 2 && echo`
+
+This line will send the chosen command to the reflector and prints out its reply.
+
+## List Of Extended API-Commands
+Here we will not describe the standard-commands in the YSF protocol, but the extended command set by the pYSFReflector.
+
+The format of the answer will be the corresponding answer-code, and some values separated by `:` for each object in scope. 
+Several objects are separated by `;`.
+
+### QSRU - Query Reflector Uptime
+#### Reply
+`ASRU;57234;`
+
+#### Description
+Uptime of reflector in seconds
+
+### QSRI - Query Reflector Info
+#### Reply
+`ASRI;62829:DE Germany:YSF262 BM263:pYSFReflector:20210326:1;`
+
+#### Description
+ID:Name:Description:Software-Name:Version:Status of Regular Expression Check (can be -1/0/1)
+
+### QGWL - Query Gateway List
+#### Reply
+`AGWL;DL-LNK:161.97.73.43:57313;2622-DL:178.238.234.72:42000;DG9VH:84.58.124.6:42140;`
+
+#### Description
+Callsign:IP-Address:Port
+
+### QLHL - Query Last Heard List
+#### Reply
+`ALHL;DG9VH:DG9VH:ALL:724:29-03-2021 07-32-13:0;2622-DL:DN3VH:ALL:723:29-03-2021 07-31-52:0;`
+
+#### Description
+Gateway:Callsign:Target:id_stream:StartTime:Duration
+
+### QREJ - Query Rejected Callsigns/Gateways/IP-Addresses
+#### Reply
+`AREJ;DG9VH/CS:DG9VH400:ALL:-1:29-03-2021 12-17-08:-1;`
+
+#### Description
+Gateway/Rule that matched:Callsign:Target:Placeholder (Ignore):Timestamp:Placeholder (Ignore);
+
+### QLHD - Query Last Heard List (with distinct callsigns)
+#### Reply
+`ALHD;2622-DL:DO7VN:ALL:2:29-03-2021 12-13-27:6;2622-DL:DH1VY:ALL:1:29-03-2021 11-45-30:0;`
+
+#### Description
+Gateway:Callsign:Target:id_stream:StartTime:Duration
+
+### QRED - Query Rejected Callsigns/Gateways/IP-Addresses (with distinct data)
+#### Reply
+`ARED;DG9VH/CS:DG9VH1A:ALL:-1:29-03-2021 15-18-54:-1;`
+
+#### Description
+Gateway/Rule that matched:Callsign:Target:Placeholder (Ignore):Timestamp:Placeholder (Ignore);
+
+### QACL - Query Access Control List-Statistics
+#### Reply
+`AACL;CS/2|AL/1|GW/1|IP/0;CS:DN3VH;CS:DG9VH;AL:N0CALL;GW:DN3VH;`
+
+#### Description
+CS/Number of muted Callsigns|AL/Number of whitelisted Callsigns|GW/Number of muted Gateways|IP/Number of muted IP-Addresses;List of Entries from deny.db
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