diff --git a/slf4j-api/src/main/java/org/slf4j/StructuredData.java b/slf4j-api/src/main/java/org/slf4j/StructuredData.java
index 7e3798023..6fb978c90 100644
--- a/slf4j-api/src/main/java/org/slf4j/StructuredData.java
+++ b/slf4j-api/src/main/java/org/slf4j/StructuredData.java
@@ -45,7 +45,7 @@ public interface StructuredData extends Serializable {
    *
    * @return The structured data id.
    */
-  StructuredData.Id getId();
+  StructuredDataId getId();
 
   /**
    * A message String that is associated with the data.
@@ -91,122 +91,5 @@ public interface StructuredData extends Serializable {
    * @param maps             Additional data to include.
    * @return The formatted String.
    */
-  String asString(String format, StructuredData.Id id, Map[] maps);
-
-  /**
-   * The StructuredData identifier
-   */
-  public class Id implements Serializable {
-    private static final long serialVersionUID = 9031746276396249990L;
-
-    public static Id TIME_QUALITY = new Id("timeQuality", null,
-        new String[]{"tzKnown", "isSynced", "syncAccuracy"});
-    public static Id ORIGIN = new Id("origin", null,
-        new String[]{"ip", "enterpriseId", "software", "swVersion"});
-    public static Id META = new Id("meta", null,
-        new String[]{"sequenceId", "sysUpTime", "language"});
-
-    public static final int RESERVED = -1;
-
-    private final String name;
-    private final int enterpriseNumber;
-    private final String[] required;
-    private final String[] optional;
-
-    protected Id(String name, String[] required, String[] optional) {
-      int index = -1;
-      if (name != null) {
-        if (name.length() > 32) {
-          throw new IllegalArgumentException("Length of id exceeds maximum of 32 characters: " + name);
-        }
-        index = name.indexOf("@");
-      }
-
-      if (index > 0) {
-        this.name = name.substring(0, index);
-        this.enterpriseNumber = Integer.parseInt(name.substring(index+1));
-      } else {
-        this.name = name;
-        this.enterpriseNumber = RESERVED;
-      }
-      this.required = required;
-      this.optional = optional;
-    }
-
-    /**
-     * A Constructor that helps conformance to RFC 5424.
-     *
-     * @param name             The name portion of the id.
-     * @param enterpriseNumber The enterprise number.
-     * @param required         The list of keys that are required for this id.
-     * @param optional         The list of keys that are optional for this id.
-     */
-    public Id(String name, int enterpriseNumber, String[] required, String[] optional) {
-      if (name == null) {
-        throw new IllegalArgumentException("No structured id name was supplied");
-      }
-      if (enterpriseNumber <= 0) {
-        throw new IllegalArgumentException("No enterprise number was supplied");
-      }
-      this.name = name;
-      this.enterpriseNumber = enterpriseNumber;
-      String id = enterpriseNumber < 0 ? name : name + "@" + enterpriseNumber;
-      if (id.length() > 32) {
-        throw new IllegalArgumentException("Length of id exceeds maximum of 32 characters: " + id);
-      }
-      this.required = required;
-      this.optional = optional;
-    }
-
-    public Id makeId(StructuredData.Id id) {
-      if (id == null) {
-        return this;
-      }
-      return makeId(id.getName(), id.getEnterpriseNumber());
-    }
-
-    public Id makeId(String defaultId, int enterpriseNumber) {
-      String id;
-      String[] req;
-      String[] opt;
-      if (enterpriseNumber <= 0) {
-        return this;
-      }
-      if (this.name != null) {
-        id = this.name;
-        req = this.required;
-        opt = this.optional;
-      } else {
-        id = defaultId;
-        req = null;
-        opt = null;
-      }
-
-      return new Id(id, enterpriseNumber, req, opt);
-    }
-
-    public String[] getRequired() {
-      return required;
-    }
-
-    public String[] getOptional() {
-      return optional;
-    }
-
-    public String getName() {
-      return name;
-    }
-
-    public int getEnterpriseNumber() {
-      return enterpriseNumber;
-    }
-
-    public boolean isReserved() {
-      return enterpriseNumber <= 0;
-    }
-
-    public String toString() {
-      return isReserved() ? name : name + "@" + enterpriseNumber;
-    }
-  }
+  String asString(String format, StructuredDataId id, Map[] maps);
 }
diff --git a/slf4j-api/src/main/java/org/slf4j/StructuredDataId.java b/slf4j-api/src/main/java/org/slf4j/StructuredDataId.java
new file mode 100644
index 000000000..ecaa19b55
--- /dev/null
+++ b/slf4j-api/src/main/java/org/slf4j/StructuredDataId.java
@@ -0,0 +1,120 @@
+package org.slf4j;
+
+import java.io.Serializable;
+
+/**
+ * The StructuredData identifier
+ */
+public class StructuredDataId implements Serializable {
+  private static final long serialVersionUID = 9031746276396249990L;
+
+  public static StructuredDataId TIME_QUALITY = new StructuredDataId("timeQuality", null,
+      new String[]{"tzKnown", "isSynced", "syncAccuracy"});
+  public static StructuredDataId ORIGIN = new StructuredDataId("origin", null,
+      new String[]{"ip", "enterpriseId", "software", "swVersion"});
+  public static StructuredDataId META = new StructuredDataId("meta", null,
+      new String[]{"sequenceId", "sysUpTime", "language"});
+
+  public static final int RESERVED = -1;
+
+  private final String name;
+  private final int enterpriseNumber;
+  private final String[] required;
+  private final String[] optional;
+
+  protected StructuredDataId(String name, String[] required, String[] optional) {
+    int index = -1;
+    if (name != null) {
+      if (name.length() > 32) {
+        throw new IllegalArgumentException("Length of id exceeds maximum of 32 characters: " + name);
+      }
+      index = name.indexOf("@");
+    }
+
+    if (index > 0) {
+      this.name = name.substring(0, index);
+      this.enterpriseNumber = Integer.parseInt(name.substring(index + 1));
+    } else {
+      this.name = name;
+      this.enterpriseNumber = RESERVED;
+    }
+    this.required = required;
+    this.optional = optional;
+  }
+
+  /**
+   * A Constructor that helps conformance to RFC 5424.
+   *
+   * @param name             The name portion of the id.
+   * @param enterpriseNumber The enterprise number.
+   * @param required         The list of keys that are required for this id.
+   * @param optional         The list of keys that are optional for this id.
+   */
+  public StructuredDataId(String name, int enterpriseNumber, String[] required, String[] optional) {
+    if (name == null) {
+      throw new IllegalArgumentException("No structured id name was supplied");
+    }
+    if (enterpriseNumber <= 0) {
+      throw new IllegalArgumentException("No enterprise number was supplied");
+    }
+    this.name = name;
+    this.enterpriseNumber = enterpriseNumber;
+    String id = enterpriseNumber < 0 ? name : name + "@" + enterpriseNumber;
+    if (id.length() > 32) {
+      throw new IllegalArgumentException("Length of id exceeds maximum of 32 characters: " + id);
+    }
+    this.required = required;
+    this.optional = optional;
+  }
+
+  public StructuredDataId makeId(StructuredDataId id) {
+    if (id == null) {
+      return this;
+    }
+    return makeId(id.getName(), id.getEnterpriseNumber());
+  }
+
+  public StructuredDataId makeId(String defaultId, int enterpriseNumber) {
+    String id;
+    String[] req;
+    String[] opt;
+    if (enterpriseNumber <= 0) {
+      return this;
+    }
+    if (this.name != null) {
+      id = this.name;
+      req = this.required;
+      opt = this.optional;
+    } else {
+      id = defaultId;
+      req = null;
+      opt = null;
+    }
+
+    return new StructuredDataId(id, enterpriseNumber, req, opt);
+  }
+
+  public String[] getRequired() {
+    return required;
+  }
+
+  public String[] getOptional() {
+    return optional;
+  }
+
+  public String getName() {
+    return name;
+  }
+
+  public int getEnterpriseNumber() {
+    return enterpriseNumber;
+  }
+
+  public boolean isReserved() {
+    return enterpriseNumber <= 0;
+  }
+
+  public String toString() {
+    return isReserved() ? name : name + "@" + enterpriseNumber;
+  }
+}
diff --git a/slf4j-api/src/main/java/org/slf4j/StructuredDataImpl.java b/slf4j-api/src/main/java/org/slf4j/StructuredDataImpl.java
index 0cdb3d196..82ebd16f2 100644
--- a/slf4j-api/src/main/java/org/slf4j/StructuredDataImpl.java
+++ b/slf4j-api/src/main/java/org/slf4j/StructuredDataImpl.java
@@ -14,19 +14,19 @@ public class StructuredDataImpl implements StructuredData {
 
   private Map data = new HashMap();
 
-  private StructuredData.Id id;
+  private StructuredDataId id;
 
   private String message;
 
   private String type;
 
   public StructuredDataImpl(final String id, final String msg, final String type) {
-    this.id = new Id(id, null, null);
+    this.id = new StructuredDataId(id, null, null);
     this.message = msg;
     this.type = type;
   }
 
-  public StructuredDataImpl(final StructuredData.Id id, final String msg, final String type) {
+  public StructuredDataImpl(final StructuredDataId id, final String msg, final String type) {
     this.id = id;
     this.message = msg;
     this.type = type;
@@ -36,15 +36,15 @@ protected StructuredDataImpl() {
 
   }
 
-  public StructuredData.Id getId() {
+  public StructuredDataId getId() {
     return id;
   }
 
   protected void setId(String id) {
-    this.id = new StructuredData.Id(id, null, null);
+    this.id = new StructuredDataId(id, null, null);
   }
 
-  protected void setId(StructuredData.Id id) {
+  protected void setId(StructuredDataId id) {
     this.id = id;
   }
 
@@ -96,7 +96,7 @@ public String asString(String format) {
    * @param maps Additional data to include.
    * @return The formatted String.
    */
-  public final String asString(String format, StructuredData.Id structuredDataId, Map[] maps) {
+  public final String asString(String format, StructuredDataId structuredDataId, Map[] maps) {
     StringBuffer sb = new StringBuffer();
     boolean full = FULL.equals(format);
     if (full) {
@@ -106,7 +106,7 @@ public final String asString(String format, StructuredData.Id structuredDataId,
       }
       sb.append(getType()).append(" ");
     }
-    StructuredData.Id id = getId();
+    StructuredDataId id = getId();
     if (id != null) {
       id = id.makeId(structuredDataId);
     } else {
diff --git a/slf4j-ext/src/main/java/org/slf4j/ext/EventData.java b/slf4j-ext/src/main/java/org/slf4j/ext/EventData.java
index 254133c04..b24f88175 100755
--- a/slf4j-ext/src/main/java/org/slf4j/ext/EventData.java
+++ b/slf4j-ext/src/main/java/org/slf4j/ext/EventData.java
@@ -23,7 +23,7 @@
 package org.slf4j.ext;
 
 import org.slf4j.StructuredDataImpl;
-import org.slf4j.StructuredData;
+import org.slf4j.StructuredDataId;
 
 import java.io.Serializable;
 import java.io.ByteArrayInputStream;
@@ -386,7 +386,7 @@ public void putAll(Map<? extends String, ?> map) {
     public Object remove(Object key) {
       Object oldValue = get(key);
       if (EVENT_ID.equals(key)) {
-        setId((StructuredData.Id) null);
+        setId((StructuredDataId) null);
       } else if (EVENT_MESSAGE.equals(key)) {
         setMessage(null);
       } else if (EVENT_TYPE.equals(key)) {