diff --git a/ConfigLib-Bukkit/src/main/resources/plugin.yml b/ConfigLib-Bukkit/src/main/resources/plugin.yml
index 688abcc..5b27cae 100644
--- a/ConfigLib-Bukkit/src/main/resources/plugin.yml
+++ b/ConfigLib-Bukkit/src/main/resources/plugin.yml
@@ -1,5 +1,5 @@
 name: ConfigLib
 author: Exlll
 
-version: 2.1.0
+version: 2.2.0
 main: de.exlll.configlib.ConfigLib
\ No newline at end of file
diff --git a/ConfigLib-Bungee/src/main/resources/plugin.yml b/ConfigLib-Bungee/src/main/resources/plugin.yml
index 688abcc..5b27cae 100644
--- a/ConfigLib-Bungee/src/main/resources/plugin.yml
+++ b/ConfigLib-Bungee/src/main/resources/plugin.yml
@@ -1,5 +1,5 @@
 name: ConfigLib
 author: Exlll
 
-version: 2.1.0
+version: 2.2.0
 main: de.exlll.configlib.ConfigLib
\ No newline at end of file
diff --git a/ConfigLib-Core/src/main/java/de/exlll/configlib/Configuration.java b/ConfigLib-Core/src/main/java/de/exlll/configlib/Configuration.java
index 0689998..501ae1d 100644
--- a/ConfigLib-Core/src/main/java/de/exlll/configlib/Configuration.java
+++ b/ConfigLib-Core/src/main/java/de/exlll/configlib/Configuration.java
@@ -1,5 +1,6 @@
 package de.exlll.configlib;
 
+import de.exlll.configlib.FieldMapper.MappingInfo;
 import de.exlll.configlib.filter.FieldFilter;
 import de.exlll.configlib.filter.FieldFilters;
 import de.exlll.configlib.format.FieldNameFormatter;
@@ -45,7 +46,9 @@ public abstract class Configuration<C extends Configuration<C>> {
     public final void save() {
         try {
             preSave();
-            Map<String, Object> map = FieldMapper.instanceToMap(this, props);
+            MappingInfo mappingInfo = MappingInfo.from(this);
+            Map<String, Object> map = FieldMapper
+                    .instanceToMap(this, mappingInfo);
             getSource().saveConfiguration(getThis(), map);
         } catch (IOException e) {
             throw new ConfigurationStoreException(e);
@@ -63,7 +66,8 @@ public abstract class Configuration<C extends Configuration<C>> {
     public final void load() {
         try {
             Map<String, Object> map = getSource().loadConfiguration(getThis());
-            FieldMapper.instanceFromMap(this, map, props);
+            MappingInfo mappingInfo = MappingInfo.from(this);
+            FieldMapper.instanceFromMap(this, map, mappingInfo);
             postLoad();
         } catch (IOException e) {
             throw new ConfigurationStoreException(e);
@@ -100,6 +104,10 @@ public abstract class Configuration<C extends Configuration<C>> {
      */
     protected void postLoad() {}
 
+    Properties getProperties() {
+        return props;
+    }
+
     /**
      * Instances of a {@code Properties} class are used to configure different
      * aspects of a configuration.
diff --git a/ConfigLib-Core/src/main/java/de/exlll/configlib/Converter.java b/ConfigLib-Core/src/main/java/de/exlll/configlib/Converter.java
index d7ad86b..e6fa70f 100644
--- a/ConfigLib-Core/src/main/java/de/exlll/configlib/Converter.java
+++ b/ConfigLib-Core/src/main/java/de/exlll/configlib/Converter.java
@@ -1,5 +1,6 @@
 package de.exlll.configlib;
 
+import de.exlll.configlib.FieldMapper.MappingInfo;
 import de.exlll.configlib.annotation.ElementType;
 
 import java.lang.reflect.Field;
@@ -10,21 +11,21 @@ import java.lang.reflect.Field;
  * <p>
  * Implementations must have a no-args constructor.
  *
- * @param <F> the type of the field value
- * @param <T> the type of the converted value
+ * @param <S> the source type
+ * @param <T> the target type
  */
-public interface Converter<F, T> {
+public interface Converter<S, T> {
     /**
      * Converts a field value to an object that can be stored by a
      * {@code ConfigurationSource}.
      * <p>
-     * If this method returns null, a {@code ConfigurationException} will be thrown.
+     * If this method returns null, a {@code ConfigurationException} is thrown.
      *
      * @param element field value that is converted
      * @param info    information about the current conversion step
      * @return converted field value
      */
-    T convertTo(F element, ConversionInfo info);
+    T convertTo(S element, ConversionInfo info);
 
     /**
      * Executes some action before the field value is converted.
@@ -43,7 +44,7 @@ public interface Converter<F, T> {
      * @param info    information about the current conversion step
      * @return the element's original representation
      */
-    F convertFrom(T element, ConversionInfo info);
+    S convertFrom(T element, ConversionInfo info);
 
     /**
      * Executes some action before the converted field value is converted back
@@ -58,6 +59,7 @@ public interface Converter<F, T> {
      * configuration, configuration element, and the conversion step.
      */
     final class ConversionInfo {
+        private final MappingInfo mappingInfo;
         private final Field field;
         private final Object instance;
         private final Object value;
@@ -70,8 +72,11 @@ public interface Converter<F, T> {
         private final int nestingLevel;
         private int currentNestingLevel;
 
-        private ConversionInfo(Field field, Object instance, Object mapValue,
-                               Configuration.Properties props) {
+        private ConversionInfo(
+                Field field, Object instance, Object mapValue,
+                MappingInfo mappingInfo
+        ) {
+            this.mappingInfo = mappingInfo;
             this.field = field;
             this.instance = instance;
             this.value = Reflect.getValue(field, instance);
@@ -79,7 +84,7 @@ public interface Converter<F, T> {
             this.fieldType = field.getType();
             this.valueType = value.getClass();
             this.fieldName = field.getName();
-            this.props = props;
+            this.props = mappingInfo.getProperties();
             this.elementType = elementType(field);
             this.nestingLevel = nestingLevel(field);
         }
@@ -100,14 +105,17 @@ public interface Converter<F, T> {
             return -1;
         }
 
-        static ConversionInfo of(Field field, Object instance,
-                                 Configuration.Properties props) {
-            return new ConversionInfo(field, instance, null, props);
+        static ConversionInfo from(
+                Field field, Object instance, MappingInfo mappingInfo
+        ) {
+            return new ConversionInfo(field, instance, null, mappingInfo);
         }
 
-        static ConversionInfo of(Field field, Object instance, Object mapValue,
-                                 Configuration.Properties props) {
-            return new ConversionInfo(field, instance, mapValue, props);
+        static ConversionInfo from(
+                Field field, Object instance, Object mapValue,
+                MappingInfo mappingInfo
+        ) {
+            return new ConversionInfo(field, instance, mapValue, mappingInfo);
         }
 
         /**
@@ -215,5 +223,9 @@ public interface Converter<F, T> {
         void incCurrentNestingLevel() {
             currentNestingLevel++;
         }
+
+        MappingInfo getMappingInfo() {
+            return this.mappingInfo;
+        }
     }
 }
diff --git a/ConfigLib-Core/src/main/java/de/exlll/configlib/Converters.java b/ConfigLib-Core/src/main/java/de/exlll/configlib/Converters.java
index 95404f6..fcb1fbc 100644
--- a/ConfigLib-Core/src/main/java/de/exlll/configlib/Converters.java
+++ b/ConfigLib-Core/src/main/java/de/exlll/configlib/Converters.java
@@ -366,7 +366,7 @@ final class Converters {
             return o -> {
                 Map<String, Object> map = toTypeMap(o, null);
                 Object inst = Reflect.newInstance(info.getElementType());
-                FieldMapper.instanceFromMap(inst, map, info.getProperties());
+                FieldMapper.instanceFromMap(inst, map, info.getMappingInfo());
                 return inst;
             };
         } else if ((element instanceof String) && currentLevelSameAsExpected) {
@@ -524,7 +524,7 @@ final class Converters {
 
         @Override
         public Object convertTo(Object element, ConversionInfo info) {
-            return FieldMapper.instanceToMap(element, info.getProperties());
+            return FieldMapper.instanceToMap(element, info.getMappingInfo());
         }
 
         @Override
@@ -538,7 +538,7 @@ final class Converters {
             checkElementIsConvertibleToConfigurationElement(element, info);
             Object newInstance = Reflect.newInstance(info.getValueType());
             Map<String, Object> typeMap = toTypeMap(element, info.getFieldName());
-            FieldMapper.instanceFromMap(newInstance, typeMap, info.getProperties());
+            FieldMapper.instanceFromMap(newInstance, typeMap, info.getMappingInfo());
             return newInstance;
         }
 
diff --git a/ConfigLib-Core/src/main/java/de/exlll/configlib/FieldMapper.java b/ConfigLib-Core/src/main/java/de/exlll/configlib/FieldMapper.java
index 85c165a..727be3f 100644
--- a/ConfigLib-Core/src/main/java/de/exlll/configlib/FieldMapper.java
+++ b/ConfigLib-Core/src/main/java/de/exlll/configlib/FieldMapper.java
@@ -1,6 +1,7 @@
 package de.exlll.configlib;
 
 import de.exlll.configlib.Converter.ConversionInfo;
+import de.exlll.configlib.annotation.Format;
 import de.exlll.configlib.filter.FieldFilter;
 import de.exlll.configlib.format.FieldNameFormatter;
 
@@ -13,14 +14,13 @@ import static de.exlll.configlib.Validator.*;
 enum FieldMapper {
     ;
 
-    static Map<String, Object> instanceToMap(
-            Object inst, Configuration.Properties props
-    ) {
+    static Map<String, Object> instanceToMap(Object inst, MappingInfo mappingInfo) {
         Map<String, Object> map = new LinkedHashMap<>();
+        Configuration.Properties props = mappingInfo.getProperties();
         FieldFilter filter = props.getFilter();
         for (Field field : filter.filterDeclaredFieldsOf(inst.getClass())) {
-            Object val = toConvertibleObject(field, inst, props);
-            FieldNameFormatter fnf = props.getFormatter();
+            Object val = toConvertibleObject(field, inst, mappingInfo);
+            FieldNameFormatter fnf = selectFormatter(mappingInfo);
             String fn = fnf.fromFieldName(field.getName());
             map.put(fn, val);
         }
@@ -28,10 +28,10 @@ enum FieldMapper {
     }
 
     private static Object toConvertibleObject(
-            Field field, Object instance, Configuration.Properties props
+            Field field, Object instance, MappingInfo mappingInfo
     ) {
         checkDefaultValueNull(field, instance);
-        ConversionInfo info = ConversionInfo.of(field, instance, props);
+        ConversionInfo info = ConversionInfo.from(field, instance, mappingInfo);
         checkFieldWithElementTypeIsContainer(info);
         Object converted = Converters.convertTo(info);
         checkConverterNotReturnsNull(converted, info);
@@ -39,26 +39,27 @@ enum FieldMapper {
     }
 
     static void instanceFromMap(
-            Object inst, Map<String, Object> instMap,
-            Configuration.Properties props
+            Object inst, Map<String, Object> instMap, MappingInfo mappingInfo
     ) {
-        FieldFilter filter = props.getFilter();
+        FieldFilter filter = mappingInfo.getProperties().getFilter();
         for (Field field : filter.filterDeclaredFieldsOf(inst.getClass())) {
-            FieldNameFormatter fnf = props.getFormatter();
+            FieldNameFormatter fnf = selectFormatter(mappingInfo);
             String fn = fnf.fromFieldName(field.getName());
             Object mapValue = instMap.get(fn);
             if (mapValue != null) {
-                fromConvertedObject(field, inst, mapValue, props);
+                fromConvertedObject(field, inst, mapValue, mappingInfo);
             }
         }
     }
 
     private static void fromConvertedObject(
             Field field, Object instance, Object mapValue,
-            Configuration.Properties props
+            MappingInfo mappingInfo
     ) {
         checkDefaultValueNull(field, instance);
-        ConversionInfo info = ConversionInfo.of(field, instance, mapValue, props);
+        ConversionInfo info = ConversionInfo.from(
+                field, instance, mapValue, mappingInfo
+        );
         checkFieldWithElementTypeIsContainer(info);
         Object convert = Converters.convertFrom(info);
 
@@ -77,4 +78,43 @@ enum FieldMapper {
         Object val = Reflect.getValue(field, instance);
         checkNotNull(val, field.getName());
     }
+
+    static FieldNameFormatter selectFormatter(MappingInfo info) {
+        Configuration<?> configuration = info.getConfiguration();
+        Configuration.Properties props = info.getProperties();
+        if ((configuration != null) &&
+                Reflect.hasFormatter(configuration.getClass())) {
+            Format format = configuration.getClass()
+                    .getAnnotation(Format.class);
+            return (format.formatterClass() != FieldNameFormatter.class)
+                    ? Reflect.newInstance(format.formatterClass())
+                    : format.value();
+        }
+        return props.getFormatter();
+    }
+
+    static final class MappingInfo {
+        private final Configuration<?> configuration;
+        private final Configuration.Properties properties;
+
+        MappingInfo(
+                Configuration<?> configuration,
+                Configuration.Properties properties
+        ) {
+            this.configuration = configuration;
+            this.properties = properties;
+        }
+
+        Configuration<?> getConfiguration() {
+            return configuration;
+        }
+
+        Configuration.Properties getProperties() {
+            return properties;
+        }
+
+        static MappingInfo from(Configuration<?> configuration) {
+            return new MappingInfo(configuration, configuration.getProperties());
+        }
+    }
 }
diff --git a/ConfigLib-Core/src/main/java/de/exlll/configlib/Reflect.java b/ConfigLib-Core/src/main/java/de/exlll/configlib/Reflect.java
index f0b9814..659f814 100644
--- a/ConfigLib-Core/src/main/java/de/exlll/configlib/Reflect.java
+++ b/ConfigLib-Core/src/main/java/de/exlll/configlib/Reflect.java
@@ -2,6 +2,7 @@ package de.exlll.configlib;
 
 import de.exlll.configlib.annotation.ConfigurationElement;
 import de.exlll.configlib.annotation.Convert;
+import de.exlll.configlib.annotation.Format;
 import de.exlll.configlib.annotation.NoConvert;
 
 import java.lang.reflect.Constructor;
@@ -37,22 +38,12 @@ enum Reflect {
         return cls.isEnum();
     }
 
-    static boolean hasConverter(Field field) {
-        return field.isAnnotationPresent(Convert.class);
-    }
-
-    static boolean hasNoConvert(Field field) {
-        return field.isAnnotationPresent(NoConvert.class);
-    }
-
     static <T> T newInstance(Class<T> cls) {
         try {
             Constructor<T> constructor = cls.getDeclaredConstructor();
             constructor.setAccessible(true);
             return constructor.newInstance();
         } catch (NoSuchMethodException e) {
-            /* This exception should not be thrown because we check
-             * the presence of a no-args constructor elsewhere. */
             String msg = "Class " + cls.getSimpleName() + " doesn't have a " +
                     "no-args constructor.";
             throw new ConfigurationException(msg, e);
@@ -63,8 +54,6 @@ enum Reflect {
                     " not accessible.";
             throw new ConfigurationException(msg, e);
         } catch (InstantiationException e) {
-            /* This exception should not be thrown because
-             * we call this method only for concrete types. */
             String msg = "Class " + cls.getSimpleName() + " not instantiable.";
             throw new ConfigurationException(msg, e);
         } catch (InvocationTargetException e) {
@@ -98,6 +87,18 @@ enum Reflect {
         }
     }
 
+    static boolean hasConverter(Field field) {
+        return field.isAnnotationPresent(Convert.class);
+    }
+
+    static boolean hasNoConvert(Field field) {
+        return field.isAnnotationPresent(NoConvert.class);
+    }
+
+    static boolean hasFormatter(Class<?> cls) {
+        return cls.isAnnotationPresent(Format.class);
+    }
+
     static boolean isConfigurationElement(Class<?> cls) {
         return cls.isAnnotationPresent(ConfigurationElement.class);
     }
diff --git a/ConfigLib-Core/src/main/java/de/exlll/configlib/annotation/ElementType.java b/ConfigLib-Core/src/main/java/de/exlll/configlib/annotation/ElementType.java
index c528c88..92bf1f6 100644
--- a/ConfigLib-Core/src/main/java/de/exlll/configlib/annotation/ElementType.java
+++ b/ConfigLib-Core/src/main/java/de/exlll/configlib/annotation/ElementType.java
@@ -24,7 +24,17 @@ import java.lang.annotation.Target;
 @Target(java.lang.annotation.ElementType.FIELD)
 @Retention(RetentionPolicy.RUNTIME)
 public @interface ElementType {
+    /**
+     * Returns the type of elements a {@code Collection} or {@code Map} contains.
+     *
+     * @return type of elements.
+     */
     Class<?> value();
 
+    /**
+     * Returns the nesting level
+     *
+     * @return nesting level
+     */
     int nestingLevel() default 0;
 }
diff --git a/ConfigLib-Core/src/main/java/de/exlll/configlib/annotation/Format.java b/ConfigLib-Core/src/main/java/de/exlll/configlib/annotation/Format.java
new file mode 100644
index 0000000..749eaba
--- /dev/null
+++ b/ConfigLib-Core/src/main/java/de/exlll/configlib/annotation/Format.java
@@ -0,0 +1,38 @@
+package de.exlll.configlib.annotation;
+
+import de.exlll.configlib.format.FieldNameFormatter;
+import de.exlll.configlib.format.FieldNameFormatters;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Indicates that a specific {@code FieldNameFormatter} is used. If a
+ * {@link #formatterClass()} is specified, the {@code FieldNameFormatters}
+ * returned by {@link #value()} is ignored. The {@code formatterClass} must
+ * be instantiable and must have a no-args constructor.
+ * <p>
+ * This annotation takes precedence over the value set in properties object.
+ */
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface Format {
+    /**
+     * Returns the {@code FieldNameFormatters} instance to be for formatting.
+     * The return value of this method is ignored if a {@code formatterClass()}
+     * is set.
+     *
+     * @return {@code FieldNameFormatters} instance
+     */
+    FieldNameFormatters value() default FieldNameFormatters.IDENTITY;
+
+    /**
+     * Returns the class of a {@code FieldNameFormatter} implementation.
+     * The class must be instantiable and must have a no-args constructor.
+     *
+     * @return class of {@code FieldNameFormatter} implementation
+     */
+    Class<? extends FieldNameFormatter> formatterClass() default FieldNameFormatter.class;
+}
diff --git a/ConfigLib-Core/src/main/java/de/exlll/configlib/format/FieldNameFormatters.java b/ConfigLib-Core/src/main/java/de/exlll/configlib/format/FieldNameFormatters.java
index 310e980..76e2983 100644
--- a/ConfigLib-Core/src/main/java/de/exlll/configlib/format/FieldNameFormatters.java
+++ b/ConfigLib-Core/src/main/java/de/exlll/configlib/format/FieldNameFormatters.java
@@ -31,5 +31,25 @@ public enum FieldNameFormatters implements FieldNameFormatter {
             }
             return builder.toString();
         }
+    },
+    /**
+     * Represents a {@code FieldNameFormatter} that transforms <i>camelCase</i> to
+     * <i>UPPER_UNDERSCORE</i>.
+     * <p>
+     * For example, <i>myPrivateField</i> becomes <i>MY_PRIVATE_FIELD</i>.
+     */
+    UPPER_UNDERSCORE {
+        @Override
+        public String fromFieldName(String fieldName) {
+            StringBuilder builder = new StringBuilder(fieldName.length());
+            for (char c : fieldName.toCharArray()) {
+                if (Character.isLowerCase(c)) {
+                    builder.append(Character.toUpperCase(c));
+                } else if (Character.isUpperCase(c)) {
+                    builder.append('_').append(c);
+                }
+            }
+            return builder.toString();
+        }
     }
 }
diff --git a/ConfigLib-Core/src/test/java/de/exlll/configlib/FieldMapperHelpers.java b/ConfigLib-Core/src/test/java/de/exlll/configlib/FieldMapperHelpers.java
index e072e72..31aa4ea 100644
--- a/ConfigLib-Core/src/test/java/de/exlll/configlib/FieldMapperHelpers.java
+++ b/ConfigLib-Core/src/test/java/de/exlll/configlib/FieldMapperHelpers.java
@@ -1,5 +1,6 @@
 package de.exlll.configlib;
 
+import de.exlll.configlib.FieldMapper.MappingInfo;
 import de.exlll.configlib.annotation.ConfigurationElement;
 
 import java.util.Map;
@@ -72,7 +73,8 @@ public class FieldMapperHelpers {
     public static Map<String, Object> instanceToMap(
             Object o, Configuration.Properties props
     ) {
-        return FieldMapper.instanceToMap(o, props);
+        MappingInfo mappingInfo = new MappingInfo(null, props);
+        return FieldMapper.instanceToMap(o, mappingInfo);
     }
 
     public static <T> T instanceFromMap(T o, Map<String, Object> map) {
@@ -82,7 +84,8 @@ public class FieldMapperHelpers {
     public static <T> T instanceFromMap(
             T o, Map<String, Object> map, Configuration.Properties props
     ) {
-        FieldMapper.instanceFromMap(o, map, props);
+        MappingInfo mappingInfo = new MappingInfo(null, props);
+        FieldMapper.instanceFromMap(o, map, mappingInfo);
         return o;
     }
 }
diff --git a/ConfigLib-Core/src/test/java/de/exlll/configlib/FieldMapperTest.java b/ConfigLib-Core/src/test/java/de/exlll/configlib/FieldMapperTest.java
index b36c476..ee77a3e 100644
--- a/ConfigLib-Core/src/test/java/de/exlll/configlib/FieldMapperTest.java
+++ b/ConfigLib-Core/src/test/java/de/exlll/configlib/FieldMapperTest.java
@@ -1,11 +1,16 @@
 package de.exlll.configlib;
 
 import de.exlll.configlib.Converter.ConversionInfo;
+import de.exlll.configlib.FieldMapper.MappingInfo;
 import de.exlll.configlib.annotation.ElementType;
+import de.exlll.configlib.annotation.Format;
 import de.exlll.configlib.annotation.NoConvert;
 import de.exlll.configlib.classes.TestClass;
 import de.exlll.configlib.classes.TestSubClass;
 import de.exlll.configlib.classes.TestSubClassConverter;
+import de.exlll.configlib.configs.mem.InSharedMemoryConfiguration;
+import de.exlll.configlib.configs.yaml.YamlConfiguration.YamlProperties;
+import de.exlll.configlib.format.FieldNameFormatter;
 import de.exlll.configlib.format.FieldNameFormatters;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -32,6 +37,10 @@ class FieldMapperTest {
     private static final TestClass t = TestClass.TEST_VALUES;
     private static final Configuration.Properties DEFAULT =
             Configuration.Properties.builder().build();
+    private static final YamlProperties WITH_UPPER_FORMATTER = YamlProperties
+            .builder()
+            .setFormatter(FieldNameFormatters.UPPER_UNDERSCORE)
+            .build();
     private static final Map<String, Object> map = instanceToMap(
             TestClass.TEST_VALUES, DEFAULT
     );
@@ -41,7 +50,8 @@ class FieldMapperTest {
     @BeforeEach
     void setUp() {
         tmp = new TestClass();
-        FieldMapper.instanceFromMap(tmp, map, DEFAULT);
+        MappingInfo mappingInfo = MappingInfo.from(tmp);
+        FieldMapper.instanceFromMap(tmp, map, mappingInfo);
     }
 
     @Test
@@ -377,7 +387,8 @@ class FieldMapperTest {
         } catch (NoSuchFieldException e) {
             e.printStackTrace();
         }
-        return ConversionInfo.of(field, o, null, null);
+        MappingInfo mappingInfo = new MappingInfo(null, WITH_UPPER_FORMATTER);
+        return ConversionInfo.from(field, o, mappingInfo);
     }
 
     private static ConversionInfo newInfo(String fieldName) {
@@ -502,4 +513,80 @@ class FieldMapperTest {
         assertThat(a.d, is(4));
         assertThat(a.e, is(5));
     }
+
+    @Test
+    void selectFieldNameFormatterReturnsPropertiesIfNoFormatAnnotation() {
+        class A extends InSharedMemoryConfiguration {
+            protected A() { super(WITH_UPPER_FORMATTER); }
+        }
+        A a = new A();
+        FieldNameFormatter fnf = FieldMapper.selectFormatter(MappingInfo.from(a));
+        assertThat(fnf, sameInstance(FieldNameFormatters.UPPER_UNDERSCORE));
+    }
+
+    @Test
+    void selectFieldNameFormatterReturnsIfFormatAnnotation() {
+        @Format(FieldNameFormatters.LOWER_UNDERSCORE)
+        class A extends InSharedMemoryConfiguration {
+            protected A() { super(WITH_UPPER_FORMATTER); }
+        }
+        @Format(formatterClass = MyFormatter.class)
+        class B extends InSharedMemoryConfiguration {
+            protected B() { super(WITH_UPPER_FORMATTER); }
+        }
+        A a = new A();
+        FieldNameFormatter fnf = FieldMapper.selectFormatter(MappingInfo.from(a));
+        assertThat(fnf, sameInstance(FieldNameFormatters.LOWER_UNDERSCORE));
+
+        B b = new B();
+        fnf = FieldMapper.selectFormatter(MappingInfo.from(b));
+        assertThat(fnf, instanceOf(MyFormatter.class));
+    }
+
+    @Test
+    void formatterClassTakesPrecedence() {
+        @Format(
+                value = FieldNameFormatters.LOWER_UNDERSCORE,
+                formatterClass = MyFormatter.class
+        )
+        class A extends InSharedMemoryConfiguration {
+            protected A() { super(WITH_UPPER_FORMATTER); }
+        }
+        A a = new A();
+        FieldNameFormatter fnf = FieldMapper.selectFormatter(MappingInfo.from(a));
+        assertThat(fnf, instanceOf(MyFormatter.class));
+    }
+
+    private static final class MyFormatter implements FieldNameFormatter {
+        @Override
+        public String fromFieldName(String fieldName) {
+            return fieldName;
+        }
+    }
+
+    @Test
+    void fieldMapperUsesSelectFieldNameFormatter() {
+        @Format(FieldNameFormatters.LOWER_UNDERSCORE)
+        class A extends InSharedMemoryConfiguration {
+            private int abc = 1;
+            private int eFg = 2;
+            private int hIJ = 3;
+
+            protected A() { super(WITH_UPPER_FORMATTER); }
+        }
+
+        A a = new A();
+        MappingInfo mappingInfo = MappingInfo.from(a);
+        Map<String, Object> map = FieldMapper.instanceToMap(a, mappingInfo);
+
+        assertThat(map.get("abc"), is(1));
+        assertThat(map.get("e_fg"), is(2));
+        assertThat(map.get("h_i_j"), is(3));
+
+        map = mapOf("abc", 4, "e_fg", 5, "h_i_j", 6);
+        FieldMapper.instanceFromMap(a, map, mappingInfo);
+        assertThat(a.abc, is(4));
+        assertThat(a.eFg, is(5));
+        assertThat(a.hIJ, is(6));
+    }
 }
\ No newline at end of file
diff --git a/ConfigLib-Core/src/test/java/de/exlll/configlib/FieldNameFormattersTest.java b/ConfigLib-Core/src/test/java/de/exlll/configlib/FieldNameFormattersTest.java
index 8f75e10..a20f975 100644
--- a/ConfigLib-Core/src/test/java/de/exlll/configlib/FieldNameFormattersTest.java
+++ b/ConfigLib-Core/src/test/java/de/exlll/configlib/FieldNameFormattersTest.java
@@ -21,4 +21,11 @@ class FieldNameFormattersTest {
 
         assertThat(formatter.fromFieldName("fieldNameFormat"), is("field_name_format"));
     }
+
+    @Test
+    void upperUnderscoreConvertsFromAndToCamelCase() {
+        FieldNameFormatter formatter = FieldNameFormatters.UPPER_UNDERSCORE;
+
+        assertThat(formatter.fromFieldName("fieldNameFormat"), is("FIELD_NAME_FORMAT"));
+    }
 }
\ No newline at end of file
diff --git a/README.md b/README.md
index 9c4455f..a8e7a7b 100644
--- a/README.md
+++ b/README.md
@@ -293,6 +293,16 @@ YamlProperties properties = YamlProperties.builder()
                 .build();
 ```
 
+Alternatively, you can annotate your `Configuration` class with the `@Format` annotation. The `FieldNameFormatter`
+returned by this annotation takes precedence over the `FieldNameFormatter` returned by a `Properties` object.
+
+```java
+@Format(FieldNameFormatters.UPPER_UNDERSCORE)
+class MyConfiguration extends YamlConfiguration {
+   // ...
+}
+```
+
 Note: You should neither remove nor replace a formatter with one that has a different formatting style because this
 could break existing configurations.
 
@@ -465,14 +475,14 @@ public final class DatabasePlugin extends JavaPlugin {
 <dependency>
     <groupId>de.exlll</groupId>
     <artifactId>configlib-bukkit</artifactId>
-    <version>2.1.0</version>
+    <version>2.2.0</version>
 </dependency>
 
 <!-- for Bungee plugins -->
 <dependency>
     <groupId>de.exlll</groupId>
     <artifactId>configlib-bungee</artifactId>
-    <version>2.1.0</version>
+    <version>2.2.0</version>
 </dependency>
 ```
 #### Gradle
@@ -484,9 +494,9 @@ repositories {
 }
 dependencies {
     // for Bukkit plugins
-    compile group: 'de.exlll', name: 'configlib-bukkit', version: '2.1.0'
+    compile group: 'de.exlll', name: 'configlib-bukkit', version: '2.2.0'
 
     // for Bungee plugins
-    compile group: 'de.exlll', name: 'configlib-bungee', version: '2.1.0'
+    compile group: 'de.exlll', name: 'configlib-bungee', version: '2.2.0'
 }
 ```
\ No newline at end of file
diff --git a/build.gradle b/build.gradle
index d0ae347..61d1082 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,6 +1,6 @@
 allprojects {
     group 'de.exlll'
-    version '2.1.0'
+    version '2.2.0'
 }
 subprojects {
     apply plugin: 'java'