diff --git a/include/spdlog/async_logger-inl.h b/include/spdlog/async_logger-inl.h
index cde73f90..382ef07a 100644
--- a/include/spdlog/async_logger-inl.h
+++ b/include/spdlog/async_logger-inl.h
@@ -57,15 +57,15 @@ SPDLOG_LOGGER_CATCH(source_loc())
 //
 // backend functions - called from the thread pool to do the actual job
 //
-SPDLOG_INLINE void spdlog::async_logger::backend_sink_it_(const details::log_msg &msg) {
+SPDLOG_INLINE void spdlog::async_logger::backend_sink_it_(const details::log_msg &incoming_log_msg) {
     for (auto &sink : sinks_) {
-        if (sink->should_log(msg.level)) {
-            SPDLOG_TRY { sink->log(msg); }
-            SPDLOG_LOGGER_CATCH(msg.source)
+        if (sink->should_log(incoming_log_msg.level)) {
+            SPDLOG_TRY { sink->log(incoming_log_msg); }
+            SPDLOG_LOGGER_CATCH(incoming_log_msg.source)
         }
     }
 
-    if (should_flush_(msg)) {
+    if (should_flush_(incoming_log_msg)) {
         backend_flush_();
     }
 }
diff --git a/include/spdlog/cfg/argv.h b/include/spdlog/cfg/argv.h
index 7de2f83e..64cf3898 100644
--- a/include/spdlog/cfg/argv.h
+++ b/include/spdlog/cfg/argv.h
@@ -26,8 +26,8 @@ inline void load_argv_levels(int argc, const char **argv) {
     for (int i = 1; i < argc; i++) {
         std::string arg = argv[i];
         if (arg.find(spdlog_level_prefix) == 0) {
-            auto levels_string = arg.substr(spdlog_level_prefix.size());
-            helpers::load_levels(levels_string);
+            const auto levels_spec = arg.substr(spdlog_level_prefix.size());
+            helpers::load_levels(levels_spec);
         }
     }
 }
diff --git a/include/spdlog/cfg/env.h b/include/spdlog/cfg/env.h
index 47bf61c7..cb153e05 100644
--- a/include/spdlog/cfg/env.h
+++ b/include/spdlog/cfg/env.h
@@ -26,9 +26,9 @@
 namespace spdlog {
 namespace cfg {
 inline void load_env_levels(const char* var = "SPDLOG_LEVEL") {
-    auto env_val = details::os::getenv(var);
-    if (!env_val.empty()) {
-        helpers::load_levels(env_val);
+    const auto levels_spec = details::os::getenv(var);
+    if (!levels_spec.empty()) {
+        helpers::load_levels(levels_spec);
     }
 }
 
diff --git a/include/spdlog/cfg/helpers-inl.h b/include/spdlog/cfg/helpers-inl.h
index 6ed86955..01050367 100644
--- a/include/spdlog/cfg/helpers-inl.h
+++ b/include/spdlog/cfg/helpers-inl.h
@@ -70,12 +70,12 @@ inline std::unordered_map<std::string, std::string> extract_key_vals_(const std:
     return rv;
 }
 
-SPDLOG_INLINE void load_levels(const std::string &input) {
-    if (input.empty() || input.size() >= 32768) {
+SPDLOG_INLINE void load_levels(const std::string &levels_spec) {
+    if (levels_spec.empty() || levels_spec.size() >= 32768) {
         return;
     }
 
-    auto key_vals = extract_key_vals_(input);
+    auto key_vals = extract_key_vals_(levels_spec);
     std::unordered_map<std::string, level::level_enum> levels;
     level::level_enum global_level = level::info;
     bool global_level_found = false;
@@ -83,7 +83,7 @@ SPDLOG_INLINE void load_levels(const std::string &input) {
     for (auto &name_level : key_vals) {
         const auto &logger_name = name_level.first;
         const auto &level_name = to_lower_(name_level.second);
-        auto level = level::from_str(level_name);
+        const auto level = level::from_str(level_name);
         // ignore unrecognized level names
         if (level == level::off && level_name != "off") {
             continue;
diff --git a/include/spdlog/cfg/helpers.h b/include/spdlog/cfg/helpers.h
index d09a1e97..25590e4e 100644
--- a/include/spdlog/cfg/helpers.h
+++ b/include/spdlog/cfg/helpers.h
@@ -18,7 +18,7 @@ namespace helpers {
 // turn off all logging except for logger1: "off,logger1=debug"
 // turn off all logging except for logger1 and logger2: "off,logger1=debug,logger2=info"
 //
-SPDLOG_API void load_levels(const std::string &txt);
+SPDLOG_API void load_levels(const std::string &levels_spec);
 }  // namespace helpers
 
 }  // namespace cfg
diff --git a/include/spdlog/spdlog.h b/include/spdlog/spdlog.h
index 681045e1..649318b2 100644
--- a/include/spdlog/spdlog.h
+++ b/include/spdlog/spdlog.h
@@ -75,7 +75,7 @@ SPDLOG_API level::level_enum get_level();
 SPDLOG_API void set_level(level::level_enum log_level);
 
 // Determine whether the default logger should log messages with a certain level
-SPDLOG_API bool should_log(level::level_enum lvl);
+SPDLOG_API bool should_log(level::level_enum log_level);
 
 // Set a global flush level
 SPDLOG_API void flush_on(level::level_enum log_level);