diff --git a/tasmota/StackThunk_light.cpp b/tasmota/StackThunk_light.cpp
index aea7ae438..8f8b9a23a 100644
--- a/tasmota/StackThunk_light.cpp
+++ b/tasmota/StackThunk_light.cpp
@@ -121,26 +121,26 @@ uint32_t stack_thunk_light_get_max_usage()
 }
 
 /* Print the stack from the first used 16-byte chunk to the top, decodable by the exception decoder */
-void stack_thunk_light_dump_stack()
-{
-  uint32_t *pos = stack_thunk_light_top;
-  while (pos < stack_thunk_light_ptr) {
-    if ((pos[0] != _stackPaint) || (pos[1] != _stackPaint) || (pos[2] != _stackPaint) || (pos[3] != _stackPaint))
-      break;
-    pos += 4;
-  }
-  ets_printf(">>>stack>>>\n");
-  while (pos < stack_thunk_light_ptr) {
-    ets_printf("%08x:  %08x %08x %08x %08x\n", (int32_t)pos, pos[0], pos[1], pos[2], pos[3]);
-    pos += 4;
-  }
-  ets_printf("<<<stack<<<\n");
-}
+// void stack_thunk_light_dump_stack()
+// {
+//   uint32_t *pos = stack_thunk_light_top;
+//   while (pos < stack_thunk_light_ptr) {
+//     if ((pos[0] != _stackPaint) || (pos[1] != _stackPaint) || (pos[2] != _stackPaint) || (pos[3] != _stackPaint))
+//       break;
+//     pos += 4;
+//   }
+//   ets_printf(">>>stack>>>\n");
+//   while (pos < stack_thunk_light_ptr) {
+//     ets_printf("%08x:  %08x %08x %08x %08x\n", (int32_t)pos, pos[0], pos[1], pos[2], pos[3]);
+//     pos += 4;
+//   }
+//   ets_printf("<<<stack<<<\n");
+// }
 
 /* Called when the stack overflow is detected by a thunk.  Main memory is corrupted at this point.  Do not return. */
 void stack_thunk_light_fatal_overflow()
 {
-    ets_printf("FATAL ERROR: BSSL stack overflow\n");
+    // ets_printf("FATAL ERROR: BSSL stack overflow\n");
     abort();
 }
 
diff --git a/tasmota/support_command.ino b/tasmota/support_command.ino
index 7faef10d5..0866d3f84 100644
--- a/tasmota/support_command.ino
+++ b/tasmota/support_command.ino
@@ -727,12 +727,12 @@ void CmndRestart(void)
   switch (XdrvMailbox.payload) {
   case 1:
     TasmotaGlobal.restart_flag = 2;
-    ResponseCmndChar(D_JSON_RESTARTING);
+    ResponseCmndChar(PSTR(D_JSON_RESTARTING));
     break;
   case 2:
     TasmotaGlobal.restart_flag = 2;
     TasmotaGlobal.restart_halt = true;
-    ResponseCmndChar(D_JSON_HALTING);
+    ResponseCmndChar(PSTR(D_JSON_HALTING));
     break;
   case -1:
     CmndCrash();    // force a crash
@@ -1208,7 +1208,7 @@ void CmndGpio(void)
     if (jsflg2) {
       ResponseClear();
     } else {
-      ResponseCmndChar(D_JSON_NOT_SUPPORTED);
+      ResponseCmndChar(PSTR(D_JSON_NOT_SUPPORTED));
     }
   }
 }
diff --git a/tasmota/support_tasmota.ino b/tasmota/support_tasmota.ino
index 597435e40..a6e0b2104 100644
--- a/tasmota/support_tasmota.ino
+++ b/tasmota/support_tasmota.ino
@@ -1169,7 +1169,7 @@ void Every250mSeconds(void)
       }
       TasmotaGlobal.restart_flag--;
       if (TasmotaGlobal.restart_flag <= 0) {
-        AddLog_P(LOG_LEVEL_INFO, PSTR(D_LOG_APPLICATION "%s"), (TasmotaGlobal.restart_halt) ? "Halted" : D_RESTARTING);
+        AddLog_P(LOG_LEVEL_INFO, PSTR(D_LOG_APPLICATION "%s"), (TasmotaGlobal.restart_halt) ? PSTR("Halted") : PSTR(D_RESTARTING));
         EspRestart();
       }
     }
diff --git a/tasmota/xdrv_01_webserver.ino b/tasmota/xdrv_01_webserver.ino
index 229d9af1d..a86e8586b 100644
--- a/tasmota/xdrv_01_webserver.ino
+++ b/tasmota/xdrv_01_webserver.ino
@@ -475,14 +475,14 @@ void StartWebserver(int type, IPAddress ipweb)
     String ipv6_addr = WifiGetIPv6();
     if (ipv6_addr!="") {
       AddLog_P(LOG_LEVEL_INFO, PSTR(D_LOG_HTTP D_WEBSERVER_ACTIVE_ON " %s%s " D_WITH_IP_ADDRESS " %s and IPv6 global address %s "),
-        NetworkHostname(), (Mdns.begun) ? ".local" : "", ipweb.toString().c_str(), ipv6_addr.c_str());
+        NetworkHostname(), (Mdns.begun) ? PSTR(".local") : "", ipweb.toString().c_str(), ipv6_addr.c_str());
     } else {
       AddLog_P(LOG_LEVEL_INFO, PSTR(D_LOG_HTTP D_WEBSERVER_ACTIVE_ON " %s%s " D_WITH_IP_ADDRESS " %s"),
-        NetworkHostname(), (Mdns.begun) ? ".local" : "", ipweb.toString().c_str());
+        NetworkHostname(), (Mdns.begun) ? PSTR(".local") : "", ipweb.toString().c_str());
     }
 #else
     AddLog_P(LOG_LEVEL_INFO, PSTR(D_LOG_HTTP D_WEBSERVER_ACTIVE_ON " %s%s " D_WITH_IP_ADDRESS " %s"),
-      NetworkHostname(), (Mdns.begun) ? ".local" : "", ipweb.toString().c_str());
+      NetworkHostname(), (Mdns.begun) ? PSTR(".local") : "", ipweb.toString().c_str());
 #endif // LWIP_IPV6 = 1
     TasmotaGlobal.rules_flag.http_init = 1;
   }
@@ -744,7 +744,7 @@ void WSContentSendStyle_P(const char* formatP, ...)
     bool sip = (static_cast<uint32_t>(WiFi.softAPIP()) != 0);
     WSContentSend_P(PSTR("<h4>%s%s (%s%s%s)</h4>"),    // tasmota.local (192.168.2.12, 192.168.4.1)
       NetworkHostname(),
-      (Mdns.begun) ? ".local" : "",
+      (Mdns.begun) ? PSTR(".local") : "",
       (lip) ? WiFi.localIP().toString().c_str() : "",
       (lip && sip) ? ", " : "",
       (sip) ? WiFi.softAPIP().toString().c_str() : "");
@@ -1230,15 +1230,15 @@ bool HandleRootStatusRefresh(void)
     uint32_t fsize = (TasmotaGlobal.devices_present < 5) ? 70 - (TasmotaGlobal.devices_present * 8) : 32;
 #ifdef USE_SONOFF_IFAN
     if (IsModuleIfan()) {
-      WSContentSend_P(HTTP_DEVICE_STATE, 36, (bitRead(TasmotaGlobal.power, 0)) ? "bold" : "normal", 54, GetStateText(bitRead(TasmotaGlobal.power, 0)));
+      WSContentSend_P(HTTP_DEVICE_STATE, 36, (bitRead(TasmotaGlobal.power, 0)) ? PSTR("bold") : PSTR("normal"), 54, GetStateText(bitRead(TasmotaGlobal.power, 0)));
       uint32_t fanspeed = GetFanspeed();
       snprintf_P(svalue, sizeof(svalue), PSTR("%d"), fanspeed);
-      WSContentSend_P(HTTP_DEVICE_STATE, 64, (fanspeed) ? "bold" : "normal", 54, (fanspeed) ? svalue : GetStateText(0));
+      WSContentSend_P(HTTP_DEVICE_STATE, 64, (fanspeed) ? PSTR("bold") : PSTR("normal"), 54, (fanspeed) ? svalue : GetStateText(0));
     } else {
 #endif  // USE_SONOFF_IFAN
       for (uint32_t idx = 1; idx <= TasmotaGlobal.devices_present; idx++) {
         snprintf_P(svalue, sizeof(svalue), PSTR("%d"), bitRead(TasmotaGlobal.power, idx -1));
-        WSContentSend_P(HTTP_DEVICE_STATE, 100 / TasmotaGlobal.devices_present, (bitRead(TasmotaGlobal.power, idx -1)) ? "bold" : "normal", fsize, (TasmotaGlobal.devices_present < 5) ? GetStateText(bitRead(TasmotaGlobal.power, idx -1)) : svalue);
+        WSContentSend_P(HTTP_DEVICE_STATE, 100 / TasmotaGlobal.devices_present, (bitRead(TasmotaGlobal.power, idx -1)) ? PSTR("bold") : PSTR("normal"), fsize, (TasmotaGlobal.devices_present < 5) ? GetStateText(bitRead(TasmotaGlobal.power, idx -1)) : svalue);
       }
 #ifdef USE_SONOFF_IFAN
     }
@@ -1438,7 +1438,7 @@ void HandleTemplateConfiguration(void)
   for (uint32_t i = 0; i < MAX_GPIO_PIN; i++) {
     if (!FlashPin(i)) {
       WSContentSend_P(PSTR("<tr><td><b><font color='#%06x'>" D_GPIO "%d</font></b></td><td%s><select id='g%d' onchange='ot(%d,this.value)'></select></td>"),
-        ((9==i)||(10==i)) ? WebColor(COL_TEXT_WARNING) : WebColor(COL_TEXT), i, (0==i) ? " style='width:150px'" : "", i, i);
+        ((9==i)||(10==i)) ? WebColor(COL_TEXT_WARNING) : WebColor(COL_TEXT), i, (0==i) ? PSTR(" style='width:150px'") : "", i, i);
       WSContentSend_P(PSTR("<td style='width:50px'><select id='h%d'></select></td></tr>"), i);
     }
   }
@@ -1824,7 +1824,7 @@ void HandleLoggingConfiguration(void)
       idx);
     for (uint32_t i = LOG_LEVEL_NONE; i <= LOG_LEVEL_DEBUG_MORE; i++) {
       WSContentSend_P(PSTR("<option%s value='%d'>%d %s</option>"),
-        (i == llevel) ? " selected" : "", i, i,
+        (i == llevel) ? PSTR(" selected") : "", i, i,
         GetTextIndexed(stemp1, sizeof(stemp1), i, kLoggingLevels));
     }
     WSContentSend_P(PSTR("</select></p>"));
@@ -1880,8 +1880,8 @@ void HandleOtherConfiguration(void)
   TemplateJson();
   char stemp[strlen(TasmotaGlobal.mqtt_data) +1];
   strlcpy(stemp, TasmotaGlobal.mqtt_data, sizeof(stemp));  // Get JSON template
-  WSContentSend_P(HTTP_FORM_OTHER, stemp, (USER_MODULE == Settings.module) ? " checked disabled" : "",
-    (Settings.flag.mqtt_enabled) ? " checked" : "",   // SetOption3 - Enable MQTT
+  WSContentSend_P(HTTP_FORM_OTHER, stemp, (USER_MODULE == Settings.module) ? PSTR(" checked disabled") : "",
+    (Settings.flag.mqtt_enabled) ? PSTR(" checked") : "",   // SetOption3 - Enable MQTT
     SettingsText(SET_FRIENDLYNAME1), SettingsText(SET_DEVICENAME));
 
   uint32_t maxfn = (TasmotaGlobal.devices_present > MAX_FRIENDLYNAMES) ? MAX_FRIENDLYNAMES : (!TasmotaGlobal.devices_present) ? 1 : TasmotaGlobal.devices_present;
@@ -1911,9 +1911,9 @@ void HandleOtherConfiguration(void)
     if (i < EMUL_MAX) {
       WSContentSend_P(PSTR("<input id='r%d' name='b2' type='radio' value='%d'%s><b>%s</b> %s<br>"),  // Different id only used for labels
         i, i,
-        (i == Settings.flag2.emulation) ? " checked" : "",
+        (i == Settings.flag2.emulation) ? PSTR(" checked") : "",
         GetTextIndexed(stemp, sizeof(stemp), i, kEmulationOptions),
-        (i == EMUL_NONE) ? "" : (i == EMUL_WEMO) ? D_SINGLE_DEVICE : D_MULTI_DEVICE);
+        (i == EMUL_NONE) ? "" : (i == EMUL_WEMO) ? PSTR(D_SINGLE_DEVICE) : PSTR(D_MULTI_DEVICE));
     }
   }
   WSContentSend_P(PSTR("</p></fieldset>"));
@@ -2086,7 +2086,7 @@ void HandleInformation(void)
 #ifdef ESP32
 #ifdef USE_ETHERNET
   if (static_cast<uint32_t>(EthernetLocalIP()) != 0) {
-    WSContentSend_P(PSTR("}1" D_HOSTNAME "}2%s%s"), EthernetHostname(), (Mdns.begun) ? ".local" : "");
+    WSContentSend_P(PSTR("}1" D_HOSTNAME "}2%s%s"), EthernetHostname(), (Mdns.begun) ? PSTR(".local") : "");
     WSContentSend_P(PSTR("}1" D_MAC_ADDRESS "}2%s"), EthernetMacAddress().c_str());
     WSContentSend_P(PSTR("}1" D_IP_ADDRESS " (eth)}2%s"), EthernetLocalIP().toString().c_str());
     WSContentSend_P(PSTR("}1<hr/>}2<hr/>"));
@@ -2096,7 +2096,7 @@ void HandleInformation(void)
   if (Settings.flag4.network_wifi) {
     int32_t rssi = WiFi.RSSI();
     WSContentSend_P(PSTR("}1" D_AP "%d " D_SSID " (" D_RSSI ")}2%s (%d%%, %d dBm)"), Settings.sta_active +1, HtmlEscape(SettingsText(SET_STASSID1 + Settings.sta_active)).c_str(), WifiGetRssiAsQuality(rssi), rssi);
-    WSContentSend_P(PSTR("}1" D_HOSTNAME "}2%s%s"), TasmotaGlobal.hostname, (Mdns.begun) ? ".local" : "");
+    WSContentSend_P(PSTR("}1" D_HOSTNAME "}2%s%s"), TasmotaGlobal.hostname, (Mdns.begun) ? PSTR(".local") : "");
 #if LWIP_IPV6
     String ipv6_addr = WifiGetIPv6();
     if (ipv6_addr != "") {
@@ -2788,7 +2788,7 @@ bool CaptivePortal(void)
   if ((WifiIsInManagerMode()) && !ValidIpAddress(Webserver->hostHeader().c_str())) {
     AddLog_P(LOG_LEVEL_DEBUG, PSTR(D_LOG_HTTP D_REDIRECTED));
 
-    Webserver->sendHeader(F("Location"), String("http://") + Webserver->client().localIP().toString(), true);
+    Webserver->sendHeader(F("Location"), String(F("http://")) + Webserver->client().localIP().toString(), true);
     WSSend(302, CT_PLAIN, "");  // Empty content inhibits Content-length header so we have to close the socket ourselves.
     Webserver->client().stop();  // Stop is needed because we sent no content length
     return true;
diff --git a/tasmota/xdrv_02_mqtt.ino b/tasmota/xdrv_02_mqtt.ino
index dcd21930f..15e99f352 100644
--- a/tasmota/xdrv_02_mqtt.ino
+++ b/tasmota/xdrv_02_mqtt.ino
@@ -1275,7 +1275,7 @@ void HandleMqttConfiguration(void)
     SettingsText(SET_MQTT_HOST),
     Settings.mqtt_port,
 #ifdef USE_MQTT_TLS
-    Mqtt.mqtt_tls ? " checked" : "",      // SetOption102 - Enable MQTT TLS
+    Mqtt.mqtt_tls ? PSTR(" checked") : "",      // SetOption102 - Enable MQTT TLS
 #endif // USE_MQTT_TLS
     Format(str, MQTT_CLIENT_ID, sizeof(str)), MQTT_CLIENT_ID, SettingsText(SET_MQTT_CLIENT));
   WSContentSend_P(HTTP_FORM_MQTT2,
diff --git a/tasmota/xdrv_09_timers.ino b/tasmota/xdrv_09_timers.ino
index c40045a31..0f6292e13 100644
--- a/tasmota/xdrv_09_timers.ino
+++ b/tasmota/xdrv_09_timers.ino
@@ -305,7 +305,7 @@ void PrepShowTimer(uint32_t index)
   char days[8] = { 0 };
   for (uint32_t i = 0; i < 7; i++) {
     uint8_t mask = 1 << i;
-    snprintf(days, sizeof(days), "%s%d", days, ((xtimer.days & mask) > 0));
+    snprintf(days, sizeof(days), PSTR("%s%d"), days, ((xtimer.days & mask) > 0));
   }
 
   char soutput[80];
@@ -857,7 +857,7 @@ void HandleTimerConfiguration(void)
   WSContentSend_P(HTTP_TIMER_SCRIPT5, MAX_TIMERS, TasmotaGlobal.devices_present);
   WSContentSend_P(HTTP_TIMER_SCRIPT6, TasmotaGlobal.devices_present);
   WSContentSendStyle_P(HTTP_TIMER_STYLE, WebColor(COL_FORM));
-  WSContentSend_P(HTTP_FORM_TIMER1, (Settings.flag3.timers_enable) ? " checked" : "");  // CMND_TIMERS
+  WSContentSend_P(HTTP_FORM_TIMER1, (Settings.flag3.timers_enable) ? PSTR(" checked") : "");  // CMND_TIMERS
   for (uint32_t i = 0; i < MAX_TIMERS; i++) {
     WSContentSend_P(PSTR("%s%u"), (i > 0) ? "," : "", Settings.timer[i].data);
   }
diff --git a/tasmota/xdrv_10_scripter.ino b/tasmota/xdrv_10_scripter.ino
index 198e58077..cd07098f8 100755
--- a/tasmota/xdrv_10_scripter.ino
+++ b/tasmota/xdrv_10_scripter.ino
@@ -4979,9 +4979,9 @@ void HandleScriptConfiguration(void) {
 #ifdef xSCRIPT_STRIP_COMMENTS
     uint16_t ssize = glob_script_mem.script_size;
     if (bitRead(Settings.rule_enabled, 1)) ssize *= 2;
-    WSContentSend_P(HTTP_FORM_SCRIPT1,1,1,bitRead(Settings.rule_enabled,0) ? " checked" : "",ssize);
+    WSContentSend_P(HTTP_FORM_SCRIPT1,1,1,bitRead(Settings.rule_enabled,0) ? PSTR(" checked") : "",ssize);
 #else
-    WSContentSend_P(HTTP_FORM_SCRIPT1,1,1,bitRead(Settings.rule_enabled,0) ? " checked" : "",glob_script_mem.script_size);
+    WSContentSend_P(HTTP_FORM_SCRIPT1,1,1,bitRead(Settings.rule_enabled,0) ? PSTR(" checked") : "",glob_script_mem.script_size);
 #endif
 
     // script is to large for WSContentSend_P
diff --git a/tasmota/xdrv_20_hue.ino b/tasmota/xdrv_20_hue.ino
index 84e9ed508..97eafbcba 100644
--- a/tasmota/xdrv_20_hue.ino
+++ b/tasmota/xdrv_20_hue.ino
@@ -175,7 +175,7 @@ String HueBridgeId(void)
   String temp = WiFi.macAddress();
   temp.replace(":", "");
   String bridgeid = temp.substring(0, 6);
-  bridgeid += "FFFE";
+  bridgeid += F("FFFE");
   bridgeid += temp.substring(6);
   return bridgeid;  // 5CCF7FFFFE139F3D
 }
diff --git a/tasmota/xdrv_23_zigbee_2a_devices_impl.ino b/tasmota/xdrv_23_zigbee_2a_devices_impl.ino
index 80a69441c..ec7d773e4 100644
--- a/tasmota/xdrv_23_zigbee_2a_devices_impl.ino
+++ b/tasmota/xdrv_23_zigbee_2a_devices_impl.ino
@@ -681,9 +681,9 @@ void Z_Device::jsonAddConfig(Z_attribute_list & attr_list) const {
   for (auto & data_elt : data) {
     char key[8];
     if (data_elt.validConfig()) {
-      snprintf_P(key, sizeof(key), "?%02X.%1X", data_elt.getEndpoint(), data_elt.getConfig());
+      snprintf_P(key, sizeof(key), PSTR("?%02X.%1X"), data_elt.getEndpoint(), data_elt.getConfig());
     } else {
-      snprintf_P(key, sizeof(key), "?%02X", data_elt.getEndpoint());
+      snprintf_P(key, sizeof(key), PSTR("?%02X"), data_elt.getEndpoint());
     }
     key[0] = Z_Data::DataTypeToChar(data_elt.getType());
     arr_data.addStr(key);
diff --git a/tasmota/xdrv_23_zigbee_5_converters.ino b/tasmota/xdrv_23_zigbee_5_converters.ino
index 5cfb19d06..fe4d219c0 100644
--- a/tasmota/xdrv_23_zigbee_5_converters.ino
+++ b/tasmota/xdrv_23_zigbee_5_converters.ino
@@ -1903,7 +1903,7 @@ void ZCLFrame::syntheticAqaraVibration(class Z_attribute_list &attr_list, class
           y = buf2.get16(2);
           x = buf2.get16(4);
           char temp[32];
-          snprintf_P(temp, sizeof(temp), "[%i,%i,%i]", x, y, z);
+          snprintf_P(temp, sizeof(temp), PSTR("[%i,%i,%i]"), x, y, z);
           attr.setStrRaw(temp);
           // calculate angles
           float X = x;
@@ -1912,7 +1912,7 @@ void ZCLFrame::syntheticAqaraVibration(class Z_attribute_list &attr_list, class
           int32_t Angle_X = 0.5f + atanf(X/sqrtf(z*z+y*y)) * f_180pi;
           int32_t Angle_Y = 0.5f + atanf(Y/sqrtf(x*x+z*z)) * f_180pi;
           int32_t Angle_Z = 0.5f + atanf(Z/sqrtf(x*x+y*y)) * f_180pi;
-          snprintf_P(temp, sizeof(temp), "[%i,%i,%i]", Angle_X, Angle_Y, Angle_Z);
+          snprintf_P(temp, sizeof(temp), PSTR("[%i,%i,%i]"), Angle_X, Angle_Y, Angle_Z);
           attr_list.addAttributePMEM(PSTR("AqaraAngles")).setStrRaw(temp);
         }
       }
diff --git a/tasmota/xdrv_23_zigbee_7_5_map.ino b/tasmota/xdrv_23_zigbee_7_5_map.ino
index 790720320..c9013b665 100644
--- a/tasmota/xdrv_23_zigbee_7_5_map.ino
+++ b/tasmota/xdrv_23_zigbee_7_5_map.ino
@@ -171,7 +171,7 @@ void Z_Mapper::dumpInternals(void) const {
     char hex[8];
     snprintf(hex, sizeof(hex), PSTR("%d"), edge.lqi);
 
-    WSContentSend_P("{from:\"0x%04X\",to:\"0x%04X\",label:\"%s\",color:\"#%03X\"},",
+    WSContentSend_P(PSTR("{from:\"0x%04X\",to:\"0x%04X\",label:\"%s\",color:\"#%03X\"},"),
                 edge.node_1, edge.node_2, (edge.lqi > 0) ? hex : "", lqi_color);
   }
   WSContentSend_P(PSTR("],"));
diff --git a/tasmota/xdrv_23_zigbee_A_impl.ino b/tasmota/xdrv_23_zigbee_A_impl.ino
index ce690c4db..ec9a454ac 100644
--- a/tasmota/xdrv_23_zigbee_A_impl.ino
+++ b/tasmota/xdrv_23_zigbee_A_impl.ino
@@ -2081,7 +2081,7 @@ void ZigbeeShow(bool json)
     if (zigbee.permit_end_time) {
       // PermitJoin in progress
 
-      WSContentSend_P(msg[ZB_WEB_PERMITJOIN_ACTIVE], D_ZIGBEE_PERMITJOIN_ACTIVE);
+      WSContentSend_P(msg[ZB_WEB_PERMITJOIN_ACTIVE], PSTR(D_ZIGBEE_PERMITJOIN_ACTIVE));
     }
 #endif
   }
diff --git a/tasmota/xdrv_28_pcf8574.ino b/tasmota/xdrv_28_pcf8574.ino
index 58bb5239c..93e8d825d 100644
--- a/tasmota/xdrv_28_pcf8574.ino
+++ b/tasmota/xdrv_28_pcf8574.ino
@@ -168,7 +168,7 @@ void HandlePcf8574(void)
 
   WSContentStart_P(D_CONFIGURE_PCF8574);
   WSContentSendStyle();
-  WSContentSend_P(HTTP_FORM_I2C_PCF8574_1, (Settings.flag3.pcf8574_ports_inverted) ? " checked" : "");  // SetOption81 - Invert all ports on PCF8574 devices
+  WSContentSend_P(HTTP_FORM_I2C_PCF8574_1, (Settings.flag3.pcf8574_ports_inverted) ? PST(" checked") : "");  // SetOption81 - Invert all ports on PCF8574 devices
   WSContentSend_P(HTTP_TABLE100);
   for (uint32_t idx = 0; idx < Pcf8574.max_devices; idx++) {
     for (uint32_t idx2 = 0; idx2 < 8; idx2++) {  // 8 ports on PCF8574
@@ -177,8 +177,8 @@ void HandlePcf8574(void)
         idx +1, idx2,
         idx2 + 8*idx,
         idx2 + 8*idx,
-        ((helper & Settings.pcf8574_config[idx]) >> idx2 == 0) ? " selected " : " ",
-        ((helper & Settings.pcf8574_config[idx]) >> idx2 == 1) ? " selected " : " "
+        ((helper & Settings.pcf8574_config[idx]) >> idx2 == 0) ? PSTR(" selected ") : " ",
+        ((helper & Settings.pcf8574_config[idx]) >> idx2 == 1) ? PSTR(" selected ") : " "
       );
     }
   }
diff --git a/tasmota/xdrv_50_filesystem.ino b/tasmota/xdrv_50_filesystem.ino
index 56d4ecfd8..dc4e93ab5 100644
--- a/tasmota/xdrv_50_filesystem.ino
+++ b/tasmota/xdrv_50_filesystem.ino
@@ -502,7 +502,7 @@ void UfsDirectory(void) {
   WSContentSend_P(UFS_FORM_FILE_UPGc, WebColor(COL_TEXT), ts, fs);
 
   if (ufs_dir) {
-    WSContentSend_P(UFS_FORM_FILE_UPGc1, WiFi.localIP().toString().c_str(),ufs_dir == 1 ? 2:1, ufs_dir == 1 ? "SDCard":"FlashFS");
+    WSContentSend_P(UFS_FORM_FILE_UPGc1, WiFi.localIP().toString().c_str(),ufs_dir == 1 ? 2:1, ufs_dir == 1 ? PSTR("SDCard"):PSTR("FlashFS"));
   }
   WSContentSend_P(UFS_FORM_FILE_UPGc2);