diff --git a/VERSION b/VERSION
index c5d54ec..7c1886b 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.0.9
+0.0.10
diff --git a/log/log.go b/log/log.go
index 9558805..b4c163b 100644
--- a/log/log.go
+++ b/log/log.go
@@ -9,6 +9,34 @@ import (
 	"golang.org/x/term"
 )
 
+// Default values for the log configuration.
+const (
+	// DefaultLevel is the default log level.
+	DefaultLevel = LevelInfo
+	// Default report caller flag in configuration.
+	DefaultCaller = false
+	// TImeFormat is defining default time format.
+	DefaultTimeFormat = "2006-01-02 15:04:05.999999"
+)
+
+// Default values for the log formatter.
+var (
+	// DefaultLevelColors is the default color mapping for the log levels.
+	DefaultLevelColors = []string{
+		ColorPanic, ColorFatal, ColorError,
+		ColorWarn, ColorInfo, ColorDebug, ColorTrace, ColorField,
+	}
+
+	// DefaultLevelNames is the default name mapping for the log levels.
+	DefaultLevelNames = []string{
+		"PANIC", "FATAL", "ERROR", "WARN",
+		"INFO", "DEBUG", "TRACE", "-",
+	}
+
+	// DefaultErrorName is the default name used for marking errors.
+	DefaultErrorName = "error"
+)
+
 // Log levels.
 const (
 	// LevelPanic is the panic log level.
@@ -120,26 +148,6 @@ const (
 	ColorTrace = ColorMagenta
 	// ColorField is the color code for fields.
 	ColorField = ColorGray
-
-	// TImeFormat is defining default time format.
-	DefaultTimeFormat = "2006-01-02 15:04:05.999999"
-)
-
-var (
-	// DefaultLevelColors is the default color mapping for the log levels.
-	DefaultLevelColors = []string{
-		ColorPanic, ColorFatal, ColorError,
-		ColorWarn, ColorInfo, ColorDebug, ColorTrace, ColorField,
-	}
-
-	// DefaultLevelNames is the default name mapping for the log levels.
-	DefaultLevelNames = []string{
-		"PANIC", "FATAL", "ERROR", "WARN",
-		"INFO", "DEBUG", "TRACE", "-",
-	}
-
-	// DefaultErrorName is the default name used for marking errors.
-	DefaultErrorName = "error"
 )
 
 // ColorModeString is the color mode used for logging.
diff --git a/log/log_test.go b/log/log_test.go
index 620df3d..79f94df 100644
--- a/log/log_test.go
+++ b/log/log_test.go
@@ -9,13 +9,6 @@ import (
 	"github.com/tkrop/go-config/log"
 )
 
-const (
-	// Default log level in configuration.
-	defaultLogLevel = "info"
-	// Default report caller flag in configuration.
-	defaultLogCaller = false
-)
-
 var (
 	// otime is a fixed output time string for testing.
 	otime = "2024-10-01 23:07:13.891012345Z"
@@ -102,9 +95,9 @@ type setupParams struct {
 var testSetupParams = map[string]setupParams{
 	"read default config": {
 		config:           &log.Config{},
-		expectLogLevel:   defaultLogLevel,
+		expectLogLevel:   log.DefaultLevel,
 		expectTimeFormat: log.DefaultTimeFormat,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 		expectColorMode:  log.ColorOff,
 		expectOrderMode:  log.OrderOn,
 	},
@@ -115,7 +108,7 @@ var testSetupParams = map[string]setupParams{
 		},
 		expectLogLevel:   log.LevelPanic,
 		expectTimeFormat: log.DefaultTimeFormat,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 		expectColorMode:  log.ColorOff,
 		expectOrderMode:  log.OrderOn,
 	},
@@ -126,7 +119,7 @@ var testSetupParams = map[string]setupParams{
 		},
 		expectLogLevel:   log.LevelFatal,
 		expectTimeFormat: log.DefaultTimeFormat,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 		expectColorMode:  log.ColorOff,
 		expectOrderMode:  log.OrderOn,
 	},
@@ -137,7 +130,7 @@ var testSetupParams = map[string]setupParams{
 		},
 		expectLogLevel:   log.LevelError,
 		expectTimeFormat: log.DefaultTimeFormat,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 		expectColorMode:  log.ColorOff,
 		expectOrderMode:  log.OrderOn,
 	},
@@ -148,7 +141,7 @@ var testSetupParams = map[string]setupParams{
 		},
 		expectLogLevel:   log.LevelWarn,
 		expectTimeFormat: log.DefaultTimeFormat,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 		expectColorMode:  log.ColorOff,
 		expectOrderMode:  log.OrderOn,
 	},
@@ -159,7 +152,7 @@ var testSetupParams = map[string]setupParams{
 		},
 		expectLogLevel:   log.LevelWarning,
 		expectTimeFormat: log.DefaultTimeFormat,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 		expectColorMode:  log.ColorOff,
 		expectOrderMode:  log.OrderOn,
 	},
@@ -170,7 +163,7 @@ var testSetupParams = map[string]setupParams{
 		},
 		expectLogLevel:   log.LevelInfo,
 		expectTimeFormat: log.DefaultTimeFormat,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 		expectColorMode:  log.ColorOff,
 		expectOrderMode:  log.OrderOn,
 	},
@@ -181,7 +174,7 @@ var testSetupParams = map[string]setupParams{
 		},
 		expectLogLevel:   log.LevelDebug,
 		expectTimeFormat: log.DefaultTimeFormat,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 		expectColorMode:  log.ColorOff,
 		expectOrderMode:  log.OrderOn,
 	},
@@ -192,18 +185,18 @@ var testSetupParams = map[string]setupParams{
 		},
 		expectLogLevel:   log.LevelTrace,
 		expectTimeFormat: log.DefaultTimeFormat,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 		expectColorMode:  log.ColorOff,
 		expectOrderMode:  log.OrderOn,
 	},
 
 	"log level invalid": {
 		config: &log.Config{
-			Level: "detail",
+			Level: "invalid",
 		},
-		expectLogLevel:   "info",
+		expectLogLevel:   log.LevelInfo,
 		expectTimeFormat: log.DefaultTimeFormat,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 		expectColorMode:  log.ColorOff,
 		expectOrderMode:  log.OrderOn,
 	},
@@ -212,9 +205,9 @@ var testSetupParams = map[string]setupParams{
 		config: &log.Config{
 			TimeFormat: "2024-12-31",
 		},
-		expectLogLevel:   defaultLogLevel,
+		expectLogLevel:   log.DefaultLevel,
 		expectTimeFormat: "2024-12-31",
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 		expectColorMode:  log.ColorOff,
 		expectOrderMode:  log.OrderOn,
 	},
@@ -223,7 +216,7 @@ var testSetupParams = map[string]setupParams{
 		config: &log.Config{
 			Caller: true,
 		},
-		expectLogLevel:   defaultLogLevel,
+		expectLogLevel:   log.DefaultLevel,
 		expectTimeFormat: log.DefaultTimeFormat,
 		expectLogCaller:  true,
 		expectColorMode:  log.ColorOff,
@@ -234,9 +227,9 @@ var testSetupParams = map[string]setupParams{
 		config: &log.Config{
 			Formatter: log.FormatterText,
 		},
-		expectLogLevel:   defaultLogLevel,
+		expectLogLevel:   log.DefaultLevel,
 		expectTimeFormat: log.DefaultTimeFormat,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 		expectColorMode:  log.ColorOff,
 		expectOrderMode:  log.OrderOn,
 	},
@@ -245,9 +238,9 @@ var testSetupParams = map[string]setupParams{
 		config: &log.Config{
 			Formatter: log.FormatterJSON,
 		},
-		expectLogLevel:   defaultLogLevel,
+		expectLogLevel:   log.DefaultLevel,
 		expectTimeFormat: log.DefaultTimeFormat,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 		expectColorMode:  log.ColorOff,
 		expectOrderMode:  log.OrderOn,
 	},
@@ -256,9 +249,9 @@ var testSetupParams = map[string]setupParams{
 		config: &log.Config{
 			Formatter: log.FormatterPretty,
 		},
-		expectLogLevel:   defaultLogLevel,
+		expectLogLevel:   log.DefaultLevel,
 		expectTimeFormat: log.DefaultTimeFormat,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 		expectColorMode:  log.ColorOff,
 		expectOrderMode:  log.OrderOn,
 	},
@@ -268,11 +261,11 @@ var testSetupParams = map[string]setupParams{
 			Formatter: log.FormatterPretty,
 			ColorMode: log.ColorModeOn,
 		},
-		expectLogLevel:   defaultLogLevel,
+		expectLogLevel:   log.DefaultLevel,
 		expectTimeFormat: log.DefaultTimeFormat,
 		expectColorMode:  log.ColorOn,
 		expectOrderMode:  log.OrderOn,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 	},
 
 	"formatter pretty color-off": {
@@ -280,11 +273,11 @@ var testSetupParams = map[string]setupParams{
 			Formatter: log.FormatterPretty,
 			ColorMode: log.ColorModeOff,
 		},
-		expectLogLevel:   defaultLogLevel,
+		expectLogLevel:   log.DefaultLevel,
 		expectTimeFormat: log.DefaultTimeFormat,
 		expectColorMode:  log.ColorOff,
 		expectOrderMode:  log.OrderOn,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 	},
 
 	"formatter pretty color-levels": {
@@ -292,11 +285,11 @@ var testSetupParams = map[string]setupParams{
 			Formatter: log.FormatterPretty,
 			ColorMode: log.ColorModeLevels,
 		},
-		expectLogLevel:   defaultLogLevel,
+		expectLogLevel:   log.DefaultLevel,
 		expectTimeFormat: log.DefaultTimeFormat,
 		expectColorMode:  log.ColorLevels,
 		expectOrderMode:  log.OrderOn,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 	},
 
 	"formatter pretty color-fields": {
@@ -304,11 +297,11 @@ var testSetupParams = map[string]setupParams{
 			Formatter: log.FormatterPretty,
 			ColorMode: log.ColorModeFields,
 		},
-		expectLogLevel:   defaultLogLevel,
+		expectLogLevel:   log.DefaultLevel,
 		expectTimeFormat: log.DefaultTimeFormat,
 		expectColorMode:  log.ColorFields,
 		expectOrderMode:  log.OrderOn,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 	},
 
 	"formatter pretty color-any": {
@@ -316,11 +309,11 @@ var testSetupParams = map[string]setupParams{
 			Formatter: log.FormatterPretty,
 			ColorMode: "any",
 		},
-		expectLogLevel:   defaultLogLevel,
+		expectLogLevel:   log.DefaultLevel,
 		expectTimeFormat: log.DefaultTimeFormat,
 		expectColorMode:  log.ColorOff,
 		expectOrderMode:  log.OrderOn,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 	},
 
 	"formatter pretty order-on": {
@@ -328,11 +321,11 @@ var testSetupParams = map[string]setupParams{
 			Formatter: log.FormatterPretty,
 			OrderMode: log.OrderModeOn,
 		},
-		expectLogLevel:   defaultLogLevel,
+		expectLogLevel:   log.DefaultLevel,
 		expectTimeFormat: log.DefaultTimeFormat,
 		expectColorMode:  log.ColorOff,
 		expectOrderMode:  log.OrderOn,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 	},
 
 	"formatter pretty order-off": {
@@ -340,11 +333,11 @@ var testSetupParams = map[string]setupParams{
 			Formatter: log.FormatterPretty,
 			OrderMode: log.OrderModeOff,
 		},
-		expectLogLevel:   defaultLogLevel,
+		expectLogLevel:   log.DefaultLevel,
 		expectTimeFormat: log.DefaultTimeFormat,
 		expectColorMode:  log.ColorOff,
 		expectOrderMode:  log.OrderOff,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 	},
 
 	"formatter pretty order-any": {
@@ -352,10 +345,10 @@ var testSetupParams = map[string]setupParams{
 			Formatter: log.FormatterPretty,
 			OrderMode: "any",
 		},
-		expectLogLevel:   defaultLogLevel,
+		expectLogLevel:   log.DefaultLevel,
 		expectTimeFormat: log.DefaultTimeFormat,
 		expectColorMode:  log.ColorOff,
 		expectOrderMode:  log.OrderOff,
-		expectLogCaller:  defaultLogCaller,
+		expectLogCaller:  log.DefaultCaller,
 	},
 }