Add @JsonEnumDefaultValue for indicating default enum choice if no real match found

src/main/java/com/fasterxml/jackson/annotation/JsonEnumDefaultValue.java

@@ -0,0 +1,24 @@
+package com.fasterxml.jackson.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Marker annotation that can be used to define a default value
+ * used when trying to deserialize unknown Enum values.
+ * <p>
+ * This annotation is only applicable when the <code>@READ_UNKNOWN_ENUM_VALUES_USING_DEFAULT_VALUE</code>
+ * deserialization feature is enabled.
+ * <p>
+ * If the more than one enum value is marked with this annotation,
+ * the first one to be detected will be used. Which one exactly is undetermined.
+ */
+@Target(ElementType.FIELD)
+@Retention(RetentionPolicy.RUNTIME)
+@JacksonAnnotation
+public @interface JsonEnumDefaultValue
+{
+
+}