diff --git a/libraries/SITL/SITL.cpp b/libraries/SITL/SITL.cpp
index 86f5253ef5..ba891f40e1 100644
--- a/libraries/SITL/SITL.cpp
+++ b/libraries/SITL/SITL.cpp
@@ -85,7 +85,7 @@ const AP_Param::GroupInfo SIM::var_info[] = {
     // @Param: RC_FAIL
     // @DisplayName: Simulated RC signal failure
     // @Description: Allows you to emulate rc failures in sim
-    // @Values: 0:Disabled,1:No RC pusles,2:Binding pulses
+    // @Values: 0:Disabled,1:No RC pusles,2:All Channels neutral except Throttle is 950us
     // @User: Advanced
     AP_GROUPINFO("RC_FAIL",       25, SIM,  rc_fail, 0),
     AP_GROUPINFO("FLOAT_EXCEPT",  28, SIM,  float_exception, 1),
@@ -99,6 +99,11 @@ const AP_Param::GroupInfo SIM::var_info[] = {
     AP_GROUPINFO("ADSB_ALT",      47, SIM,  adsb_altitude_m, 1000),
     AP_GROUPINFO("PIN_MASK",      50, SIM,  pin_mask, 0),
     AP_GROUPINFO("ADSB_TX",       51, SIM,  adsb_tx, 0),
+    // @Param: SPEEDUP
+    // @DisplayName: Sim Speedup
+    // @Description: Runs the simulation at multiples of normal speed. Do not use if realtime physics, like RealFlight, is being used
+    // @Range: 1 10
+    // @User: Advanced    
     AP_GROUPINFO("SPEEDUP",       52, SIM,  speedup, -1),
     AP_GROUPINFO("IMU_POS",       53, SIM,  imu_pos_offset, 0),
     AP_SUBGROUPEXTENSION("",      54, SIM,  var_ins),
@@ -125,13 +130,22 @@ const AP_Param::GroupInfo SIM::var_info2[] = {
     AP_GROUPINFO("TEMP_BFACTOR", 4, SIM,  temp_baro_factor, 0),
 
     AP_GROUPINFO("WIND_DIR_Z",  10, SIM,  wind_dir_z,     0),
+    // @Param: WIND_T_
+    // @DisplayName: Wind Profile Type
+    // @Description: Selects how wind varies from surface to WIND_T_ALT
+    // @Values: 0:square law,1: none, 2:linear-see WIND_T_COEF
+    // @User: Advanced    
     AP_GROUPINFO("WIND_T"      ,15, SIM,  wind_type, SIM::WIND_TYPE_SQRT),
     // @Param: WIND_T_ALT
     // @DisplayName: Full Wind Altitude
-    // @Description: Altitude at which wind reaches full strength, rising from 0 at ground level
+    // @Description: Altitude at which wind reaches full strength, decaying from full strength as altitude lowers to ground level
     // @Units: m
     // @User: Advanced
     AP_GROUPINFO("WIND_T_ALT"  ,16, SIM,  wind_type_alt, 60),
+    // @Param: WIND_T_COEF
+    // @DisplayName: Linear Wind Curve Coeff
+    // @Description: For linear wind profile,wind is reduced by (Altitude-WIND_T_ALT) x this value
+    // @User: Advanced
     AP_GROUPINFO("WIND_T_COEF", 17, SIM,  wind_type_coef, 0.01f),
     AP_GROUPINFO("RC_CHANCOUNT",21, SIM,  rc_chancount, 16),
     // @Group: SPR_
@@ -369,6 +383,11 @@ const AP_Param::GroupInfo SIM::AirspeedParm::var_info[] = {
         // user settable parameters for the 1st airspeed sensor
     AP_GROUPINFO("RND",     1, SIM::AirspeedParm,  noise, 2.0),
     AP_GROUPINFO("OFS",     2, SIM::AirspeedParm,  offset, 2013),
+    // @Param: ARSPD_FAIL
+    // @DisplayName: Airspeed sensor failure
+    // @Description: Simulates Airspeed sensor 1 failure
+    // @Values: 0:Disabled, 1:Enabled
+    // @User: Advanced
     AP_GROUPINFO("FAIL",    3, SIM::AirspeedParm,  fail, 0),
     AP_GROUPINFO("FAILP",   4, SIM::AirspeedParm,  fail_pressure, 0),
     AP_GROUPINFO("PITOT",   5, SIM::AirspeedParm,  fail_pitot_pressure, 0),
@@ -380,6 +399,11 @@ const AP_Param::GroupInfo SIM::AirspeedParm::var_info[] = {
 #if HAL_SIM_GPS_ENABLED
 // GPS SITL parameters
 const AP_Param::GroupInfo SIM::var_gps[] = {
+    // @Param: GPS_DISABLE
+    // @DisplayName: GPS 1 disable
+    // @Description: Disables GPS 1
+    // @Values: 0:Enable, 1:GPS Disabled
+    // @User: Advanced
     AP_GROUPINFO("GPS_DISABLE",    1, SIM,  gps_disable[0], 0),
     AP_GROUPINFO("GPS_LAG_MS",     2, SIM,  gps_delay_ms[0], 100),
     AP_GROUPINFO("GPS_TYPE",       3, SIM,  gps_type[0],  GPS::Type::UBLOX),
@@ -395,7 +419,11 @@ const AP_Param::GroupInfo SIM::var_gps[] = {
     AP_GROUPINFO("GPS_HDG",       13, SIM,  gps_hdg_enabled[0], SIM::GPS_HEADING_NONE),
     AP_GROUPINFO("GPS_ACC",       14, SIM,  gps_accuracy[0], 0.3),
     AP_GROUPINFO("GPS_VERR",      15, SIM,  gps_vel_err[0], 0),
-
+    // @Param: GPS2_DISABLE
+    // @DisplayName: GPS 2 disable
+    // @Description: Disables GPS 2
+    // @Values: 0:Enable, 1:GPS Disabled
+    // @User: Advanced
     AP_GROUPINFO("GPS2_DISABLE",  30, SIM,  gps_disable[1], 1),
     AP_GROUPINFO("GPS2_LAG_MS",   31, SIM,  gps_delay_ms[1], 100),
     AP_GROUPINFO("GPS2_TYPE",     32, SIM,  gps_type[1],  GPS::Type::UBLOX),
@@ -454,12 +482,22 @@ const AP_Param::GroupInfo SIM::var_mag[] = {
 #if MAX_CONNECTED_MAGS > 7
     AP_GROUPINFO("MAG8_DEVID",    18, SIM,  mag_devid[7], 0),
 #endif
+    // @Param: MAG1_FAIL
+    // @DisplayName: MAG1 Failure
+    // @Description: Simulated failure of MAG1
+    // @Values: 0:Disabled, 1:MAG1 Failure
+    // @User: Advanced
     AP_GROUPINFO("MAG1_FAIL",     26, SIM,  mag_fail[0], 0),
 #if HAL_COMPASS_MAX_SENSORS > 1
     AP_GROUPINFO("MAG2_OFS",      19, SIM,  mag_ofs[1], 0),
     AP_GROUPINFO("MAG2_DIA",      20, SIM,  mag_diag[1], 0),
     AP_GROUPINFO("MAG2_ODI",      21, SIM,  mag_offdiag[1], 0),
     AP_GROUPINFO("MAG2_ORIENT",   22, SIM,  mag_orient[1], 0),
+    // @Param: MAG2_FAIL
+    // @DisplayName: MAG2 Failure
+    // @Description: Simulated failure of MAG2
+    // @Values: 0:Disabled, 1:MAG2 Failure
+    // @User: Advanced
     AP_GROUPINFO("MAG2_FAIL",     27, SIM,  mag_fail[1], 0),
     AP_GROUPINFO("MAG2_SCALING",  28, SIM,  mag_scaling[1], 1),
 #endif
@@ -467,6 +505,11 @@ const AP_Param::GroupInfo SIM::var_mag[] = {
     AP_GROUPINFO("MAG3_OFS",      23, SIM,  mag_ofs[2], 0),
     AP_GROUPINFO("MAG3_DIA",      24, SIM,  mag_diag[2], 0),
     AP_GROUPINFO("MAG3_ODI",      25, SIM,  mag_offdiag[2], 0),
+    // @Param: MAG3_FAIL
+    // @DisplayName: MAG3 Failure
+    // @Description: Simulated failure of MAG3
+    // @Values: 0:Disabled, 1:MAG3 Failure
+    // @User: Advanced
     AP_GROUPINFO("MAG3_FAIL",     29, SIM,  mag_fail[2], 0),
     AP_GROUPINFO("MAG3_SCALING",  30, SIM,  mag_scaling[2], 1),
     AP_GROUPINFO("MAG3_ORIENT",   36, SIM,  mag_orient[2], 0),
@@ -525,14 +568,39 @@ const AP_Param::GroupInfo SIM::var_ins[] = {
 #if INS_MAX_INSTANCES > 2
     AP_GROUPINFO("GYR3_SCALE",   16, SIM, gyro_scale[2], 0),
 #endif
+    // @Param: ACCEL1_FAIL
+    // @DisplayName: ACCEL1 Failure
+    // @Description: Simulated failure of ACCEL1
+    // @Values: 0:Disabled, 1:ACCEL1 Failure
+    // @User: Advanced
     AP_GROUPINFO("ACCEL1_FAIL",  17, SIM, accel_fail[0],  0),
 #if INS_MAX_INSTANCES > 1
+    // @Param: ACCEL2_FAIL
+    // @DisplayName: ACCEL2 Failure
+    // @Description: Simulated failure of ACCEL2
+    // @Values: 0:Disabled, 1:ACCEL2 Failure
+    // @User: Advanced
     AP_GROUPINFO("ACCEL2_FAIL",  18, SIM, accel_fail[1],  0),
 #endif
 #if INS_MAX_INSTANCES > 2
+    // @Param: ACCEL3_FAIL
+    // @DisplayName: ACCEL3 Failure
+    // @Description: Simulated failure of ACCEL3
+    // @Values: 0:Disabled, 1:ACCEL3 Failure
+    // @User: Advanced
     AP_GROUPINFO("ACCEL3_FAIL",  19, SIM, accel_fail[2],  0),
 #endif
+    // @Param: GYRO_FAIL_MSK
+    // @DisplayName: Gyro Failure Mask
+    // @Description: Determines if the gyro reading updates are stopped when for an IMU simulated failure by ACCELx_FAIL params
+    // @Values: 0:Disabled, 1:Readings stopped
+    // @User: Advanced
     AP_GROUPINFO("GYR_FAIL_MSK", 20, SIM, gyro_fail_mask,  0),
+    // @Param: ACC_FAIL_MSK
+    // @DisplayName: Accelerometer Failure Mask
+    // @Description: Determines if the acclerometer reading updates are stopped when for an IMU simulated failure by ACCELx_FAIL params
+    // @Values: 0:Disabled, 1:Readings stopped
+    // @User: Advanced
     AP_GROUPINFO("ACC_FAIL_MSK", 21, SIM, accel_fail_mask,  0),
     AP_GROUPINFO("ACC1_SCAL",    22, SIM, accel_scale[0], 0),
 #if INS_MAX_INSTANCES > 1