diff --git a/config.h b/config.h
index 0244ae8..b7b76f6 100644
--- a/config.h
+++ b/config.h
@@ -14,20 +14,22 @@
 #define BUILTIN_LED           2
 #endif
 
-#define CFG_IS_CLIENT_MODE    true
+#define CFG_IS_CLIENT_MODE    true      // false - server mode (APRS-IS gate mode)
 
+// lora pinouts, CAD and ISR usage
 #define CFG_LORA_PIN_SS       SS
 #define CFG_LORA_PIN_RST      LORA_RST
 #define CFG_LORA_PIN_DIO0     LORA_IRQ
 #ifdef USE_RADIOLIB
 #define CFG_LORA_PIN_DIO1     RADIOLIB_NC // set to your DIO1 pin number if connected
-#define CFG_LORA_USE_ISR      true
+#define CFG_LORA_USE_ISR      true        // always ON for RadioLib
 #else
 #define CFG_LORA_PIN_DIO1     LORA_IRQ  // not used in arduino-LoRa
-#define CFG_LORA_USE_ISR      false // set to true for ISR usage
+#define CFG_LORA_USE_ISR      false // set to true for ISR usage in arduino-LoRa
 #endif
 #define CFG_LORA_USE_CAD      false // set to true to utilize carrier detection
 
+// lora protocol parameters
 #define CFG_LORA_FREQ         433.775E6
 #define CFG_LORA_BW           125e3
 #define CFG_LORA_SF           12
@@ -35,30 +37,38 @@
 #define CFG_LORA_PWR          20
 #define CFG_LORA_ENABLE_CRC   true  // set to false for speech data
 
+// wifi client and AP options
+#define CFG_WIFI_ENABLE_AP    false     // run as wifi access point, for CFG_KISS_TCP_IP mode
+#define CFG_WIFI_SSID         "<ssid>"  // connect to SSID or run as this SSID in AP mode
+#define CFG_WIFI_KEY          "<key>"   // wifi key
+
+// bluetooth
 #define CFG_BT_NAME           "loraprs"
 #define CFG_BT_USE_BLE        false // set to true to use bluetooth low energy (for ios devices)
 
+// KISS protocol options
+#define CFG_KISS_EXTENSIONS   false   // true - enable modem control from application with KISS commands
+#define CFG_KISS_TCP_IP       false   // true - run as KISS TCP/IP server, no bluetooth operations performed
+
+// APRS-IS options, valid in when CFG_IS_CLIENT_MODE = false
 #define CFG_APRS_LOGIN        "NOCALL-10"
 #define CFG_APRS_PASS         "12345"
 #define CFG_APRS_FILTER	      "r/35.60/139.80/25"
 #define CFG_APRS_RAW_BKN      "NOCALL-10>APZMDM,WIDE1-1:!0000.00N/00000.00E#LoRA 433.775MHz/BW125/SF12/CR7/0x34"
 
-#define CFG_WIFI_ENABLE_AP    false
-#define CFG_WIFI_SSID         "<ssid>"
-#define CFG_WIFI_KEY          "<key>"
+// APRS-IS gateway options, valid in when CFG_IS_CLIENT_MODE = false
+#define CFG_PERSISTENT_APRS   true    // keep tcp/ip connection open (lot of traffic), otherwise connect on new packet (very rare traffic)
+#define CFG_DIGIREPEAT        false   // digirepeat incoming packets
+#define CFG_RF_TO_IS          true    // forward packets from radio to internet
+#define CFG_IS_TO_RF          false   // forward packets from internet to radio basedon CFG_APRS_FILTER
+#define CFG_BEACON            false   // enable perdiodc beacon from CFG_APRS_RAW_BKN
 
+// frequency correction for narrow band bandwidths
 #define CFG_FREQ_CORR         false   // NB! incoming interrupts may stop working on frequent corrections when enabled
 #define CFG_FREQ_CORR_DELTA   1000    //      test with your module before heavy usage
 
-#define CFG_PERSISTENT_APRS   true
-#define CFG_DIGIREPEAT        false
-#define CFG_RF_TO_IS          true
-#define CFG_IS_TO_RF          false
-#define CFG_BEACON            false
-#define CFG_KISS_EXTENSIONS   false
-#define CFG_KISS_TCP_IP       false
-
-#define CFG_PTT_ENABLE        false
-#define CFG_PTT_PIN           12
-#define CFG_PTT_TX_DELAY_MS   50
-#define CFG_PTT_TX_TAIL_MS    10
+// PTT control
+#define CFG_PTT_ENABLE        false   // enable external ptt (relay) control (for amplifier)
+#define CFG_PTT_PIN           12      // PTT pin
+#define CFG_PTT_TX_DELAY_MS   50      // time between relay swited on and transmission
+#define CFG_PTT_TX_TAIL_MS    10      // time between stop transmission and relay off