diff --git a/com.google.eclipse.protobuf.cdt/src/com/google/eclipse/protobuf/cdt/matching/MessageMatcherStrategy.java b/com.google.eclipse.protobuf.cdt/src/com/google/eclipse/protobuf/cdt/matching/MessageMatcherStrategy.java
index 695c885..1f9fe3c 100644
--- a/com.google.eclipse.protobuf.cdt/src/com/google/eclipse/protobuf/cdt/matching/MessageMatcherStrategy.java
+++ b/com.google.eclipse.protobuf.cdt/src/com/google/eclipse/protobuf/cdt/matching/MessageMatcherStrategy.java
@@ -41,7 +41,7 @@
             matches.add(uriOf(message));
             break;
           }
-          // go one level deeper.
+          // perfect segment match - go one level deeper.
           contents = contentsOf(message);
           continue;
         }
@@ -53,6 +53,7 @@
     return unmodifiableList(matches);
   }
 
+  // TODO move to ModelObjects
   private URI uriOf(EObject e) {
     Resource resource = e.eResource();
     URI uri = resource.getURI();
diff --git a/com.google.eclipse.protobuf.integration.test/src/com/google/eclipse/protobuf/model/util/Options_fieldsOf_CustomFieldOption_Test.java b/com.google.eclipse.protobuf.integration.test/src/com/google/eclipse/protobuf/model/util/Options_fieldsOf_CustomFieldOption_Test.java
new file mode 100644
index 0000000..598e753
--- /dev/null
+++ b/com.google.eclipse.protobuf.integration.test/src/com/google/eclipse/protobuf/model/util/Options_fieldsOf_CustomFieldOption_Test.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2011 Google Inc.
+ *
+ * All rights reserved. This program and the accompanying materials are made available under the terms of the Eclipse
+ * Public License v1.0 which accompanies this distribution, and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
+package com.google.eclipse.protobuf.model.util;
+
+import static com.google.eclipse.protobuf.junit.core.IntegrationTestModule.integrationTestModule;
+import static com.google.eclipse.protobuf.junit.core.XtextRule.overrideRuntimeModuleWith;
+import static org.hamcrest.core.IsEqual.equalTo;
+import static org.junit.Assert.assertThat;
+
+import java.util.List;
+
+import org.junit.*;
+
+import com.google.eclipse.protobuf.junit.core.XtextRule;
+import com.google.eclipse.protobuf.protobuf.*;
+import com.google.inject.Inject;
+
+/**
+ * Tests for <code>{@link Options#fieldsOf(AbstractCustomOption)}</code>.
+ *
+ * alruiz@google.com (Alex Ruiz)
+ */
+public class Options_fieldsOf_CustomFieldOption_Test {
+  @Rule public XtextRule xtext = overrideRuntimeModuleWith(integrationTestModule());
+
+  @Inject private Options options;
+
+  // syntax = "proto2";
+  //
+  // import 'google/protobuf/descriptor.proto';
+  //
+  // message Custom {
+  //   optional int32 count = 1;
+  // }
+  //
+  // extend google.protobuf.FieldOptions {
+  //   optional Custom custom = 1000;
+  // }
+  //
+  // message Person {
+  //   optional boolean active = 1 [(custom).count = 6];
+  // }
+  @Test public void should_return_option_field() {
+    CustomFieldOption option = xtext.find("custom", ").", CustomFieldOption.class);
+    List<OptionField> fields = option.getFields();
+    assertThat(options.fieldsOf(option), equalTo(fields));
+  }
+}
diff --git a/com.google.eclipse.protobuf.integration.test/src/com/google/eclipse/protobuf/model/util/Options_fieldsOf_CustomOption_Test.java b/com.google.eclipse.protobuf.integration.test/src/com/google/eclipse/protobuf/model/util/Options_fieldsOf_CustomOption_Test.java
new file mode 100644
index 0000000..d76df26
--- /dev/null
+++ b/com.google.eclipse.protobuf.integration.test/src/com/google/eclipse/protobuf/model/util/Options_fieldsOf_CustomOption_Test.java
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2011 Google Inc.
+ *
+ * All rights reserved. This program and the accompanying materials are made available under the terms of the Eclipse
+ * Public License v1.0 which accompanies this distribution, and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
+package com.google.eclipse.protobuf.model.util;
+
+import static com.google.eclipse.protobuf.junit.core.IntegrationTestModule.integrationTestModule;
+import static com.google.eclipse.protobuf.junit.core.XtextRule.overrideRuntimeModuleWith;
+import static org.hamcrest.core.IsEqual.equalTo;
+import static org.junit.Assert.assertThat;
+
+import java.util.List;
+
+import org.junit.*;
+
+import com.google.eclipse.protobuf.junit.core.XtextRule;
+import com.google.eclipse.protobuf.protobuf.*;
+import com.google.inject.Inject;
+
+/**
+ * Tests for <code>{@link Options#fieldsOf(AbstractCustomOption)}</code>.
+ *
+ * alruiz@google.com (Alex Ruiz)
+ */
+public class Options_fieldsOf_CustomOption_Test {
+  @Rule public XtextRule xtext = overrideRuntimeModuleWith(integrationTestModule());
+
+  @Inject private Options options;
+
+  // syntax = "proto2";
+  //
+  // import 'google/protobuf/descriptor.proto';
+  //
+  // message Custom {
+  //   optional int32 count = 1;
+  // }
+  //
+  // extend google.protobuf.FileOptions {
+  //   optional Custom custom = 1000;
+  // }
+  //
+  // option (custom).count = 6;
+  @Test public void should_return_option_field() {
+    CustomOption option = xtext.find("custom", ")", CustomOption.class);
+    List<OptionField> fields = option.getFields();
+    assertThat(options.fieldsOf(option), equalTo(fields));
+  }
+}
diff --git a/com.google.eclipse.protobuf.integration.test/src/com/google/eclipse/protobuf/model/util/Options_sourceOfLastFieldIn_CustomFieldOption_Test.java b/com.google.eclipse.protobuf.integration.test/src/com/google/eclipse/protobuf/model/util/Options_sourceOfLastFieldIn_CustomFieldOption_Test.java
index 69c785f..210e8dd 100644
--- a/com.google.eclipse.protobuf.integration.test/src/com/google/eclipse/protobuf/model/util/Options_sourceOfLastFieldIn_CustomFieldOption_Test.java
+++ b/com.google.eclipse.protobuf.integration.test/src/com/google/eclipse/protobuf/model/util/Options_sourceOfLastFieldIn_CustomFieldOption_Test.java
@@ -27,7 +27,7 @@
 public class Options_sourceOfLastFieldIn_CustomFieldOption_Test {
   @Rule public XtextRule xtext = overrideRuntimeModuleWith(integrationTestModule());
 
-  @Inject private Options fieldOptions;
+  @Inject private Options options;
 
   // syntax = "proto2";
   //
@@ -46,7 +46,7 @@
   // }
   @Test public void should_return_option_field() {
     CustomFieldOption option = xtext.find("custom", ").", CustomFieldOption.class);
-    MessageField field = (MessageField) fieldOptions.sourceOfLastFieldIn(option);
+    MessageField field = (MessageField) options.sourceOfLastFieldIn(option);
     assertThat(field.getName(), equalTo("count"));
   }
 }
diff --git a/com.google.eclipse.protobuf.test/src/com/google/eclipse/protobuf/model/util/Packages_addPackageNameSegments_Test.java b/com.google.eclipse.protobuf.test/src/com/google/eclipse/protobuf/model/util/Packages_addPackageNameSegments_Test.java
new file mode 100644
index 0000000..0c3c294
--- /dev/null
+++ b/com.google.eclipse.protobuf.test/src/com/google/eclipse/protobuf/model/util/Packages_addPackageNameSegments_Test.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2012 Google Inc.
+ *
+ * All rights reserved. This program and the accompanying materials are made available under the terms of the Eclipse
+ * Public License v1.0 which accompanies this distribution, and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
+package com.google.eclipse.protobuf.model.util;
+
+import static com.google.eclipse.protobuf.junit.core.UnitTestModule.unitTestModule;
+import static com.google.eclipse.protobuf.junit.core.XtextRule.overrideRuntimeModuleWith;
+import static com.google.eclipse.protobuf.model.util.QualifiedNameCollectionContains.contains;
+import static org.junit.Assert.*;
+
+import java.util.Collection;
+
+import org.eclipse.xtext.naming.QualifiedName;
+import org.junit.*;
+
+import com.google.eclipse.protobuf.junit.core.XtextRule;
+import com.google.eclipse.protobuf.protobuf.Package;
+import com.google.inject.Inject;
+
+/**
+ * Tests for <code>{@link Packages#addPackageNameSegments(Package, QualifiedName)}</code>
+ *
+ * @author alruiz@google.com (Alex Ruiz)
+ */
+public class Packages_addPackageNameSegments_Test {
+  @Rule public XtextRule xtext = overrideRuntimeModuleWith(unitTestModule());
+
+  @Inject private Packages packages;
+
+
+  // syntax = "proto2";
+  //
+  // package com.google.test;
+  @Test public void should_create_a_qualified_name_per_segment_in_package_name() {
+    Package aPackage = xtext.find("com.google.test", Package.class);
+    Collection<QualifiedName> names = packages.addPackageNameSegments(aPackage, QualifiedName.create("Person"));
+    assertThat(names, contains("test.Person", "google.test.Person"));
+  }
+
+  // syntax = "proto2";
+  //
+  // package google;
+  @Test public void should_return_empty_list_if_package_has_only_one_segment() {
+    Package aPackage = xtext.find("google", Package.class);
+    Collection<QualifiedName> names = packages.addPackageNameSegments(aPackage, QualifiedName.create("Person"));
+    assertTrue(names.isEmpty());
+  }
+}
diff --git a/com.google.eclipse.protobuf.test/src/com/google/eclipse/protobuf/model/util/QualifiedNameCollectionContains.java b/com.google.eclipse.protobuf.test/src/com/google/eclipse/protobuf/model/util/QualifiedNameCollectionContains.java
new file mode 100644
index 0000000..4ba52db
--- /dev/null
+++ b/com.google.eclipse.protobuf.test/src/com/google/eclipse/protobuf/model/util/QualifiedNameCollectionContains.java
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2012 Google Inc.
+ *
+ * All rights reserved. This program and the accompanying materials are made available under the terms of the Eclipse
+ * Public License v1.0 which accompanies this distribution, and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
+package com.google.eclipse.protobuf.model.util;
+
+import static com.google.common.collect.Lists.newArrayList;
+
+import java.util.*;
+
+import org.eclipse.xtext.naming.QualifiedName;
+import org.hamcrest.*;
+
+/**
+ * @author alruiz@google.com (Alex Ruiz)
+ */
+class QualifiedNameCollectionContains extends TypeSafeMatcher<Collection<QualifiedName>> {
+  private final List<String> qualifiedNames;
+
+  static QualifiedNameCollectionContains contains(String...qualifiedNames) {
+    return new QualifiedNameCollectionContains(qualifiedNames);
+  }
+
+  private QualifiedNameCollectionContains(String[] qualifiedNames) {
+    this.qualifiedNames = newArrayList(qualifiedNames);
+  }
+
+  @Override public boolean matchesSafely(Collection<QualifiedName> item) {
+    if (item.size() != qualifiedNames.size()) {
+      return false;
+    }
+    List<String> copy = newArrayList(qualifiedNames);
+    for (QualifiedName name : item) {
+      copy.remove(name.toString());
+    }
+    return copy.isEmpty();
+  }
+
+  @Override public void describeTo(Description description) {
+    description.appendValue(qualifiedNames);
+  }
+}
diff --git a/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/model/util/Packages.java b/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/model/util/Packages.java
index 52f37f4..0963f43 100644
--- a/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/model/util/Packages.java
+++ b/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/model/util/Packages.java
@@ -64,7 +64,38 @@
     return true;
   }
 
-  // TODO test and document
+  /**
+   * Adds the segments in the name of the given package to the given qualified name, creating a new qualified name per
+   * segment.
+   * <p>
+   * For example, given the following proto element:
+   *
+   * <pre>
+   * package test.alternative.names;
+   *
+   * message Person {
+   *   optional string name = 1;
+   *
+   *   enum PhoneType {
+   *     HOME = 0;
+   *     WORK = 1;
+   *   }
+   * }
+   * </pre>
+   *
+   * This method will create the following qualified names for {@code PhoneType}:
+   * <ul>
+   * <li>{@code PhoneType}</li>
+   * <li>{@code Person.PhoneType}</li>
+   * <li>{@code names.Person.PhoneType}</li>
+   * <li>{@code test.names.Person.PhoneType}</li>
+   * </ul>
+   * </p>
+   * @param p the given package.
+   * @param name the base name.
+   * @return a collection containing the created qualified names, or an empty list if the name of the given package
+   * contains zero or one segments.
+   */
   public Collection<QualifiedName> addPackageNameSegments(Package p, QualifiedName name) {
     QualifiedName current = name;
     List<String> segments = segmentsOf(p);
@@ -80,6 +111,11 @@
     return unmodifiableList(allNames);
   }
 
+  /**
+   * Returns the segments in the name of the given package.
+   * @param p the given package.
+   * @return the segments in the name of the given package.
+   */
   public List<String> segmentsOf(Package p) {
     QualifiedName name = (p == null) ? null : nameOf(p);
     if (name == null) {
@@ -90,9 +126,6 @@
 
   private QualifiedName nameOf(Package p) {
     String name = p.getName();
-    if (isEmpty(name)) {
-      return null;
-    }
-    return qualifiedNameConverter.toQualifiedName(name);
+    return (isEmpty(name)) ? null : qualifiedNameConverter.toQualifiedName(name);
   }
 }
diff --git a/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/naming/LocalNamesProvider.java b/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/naming/LocalNamesProvider.java
index 5d7b9bf..0bb3563 100644
--- a/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/naming/LocalNamesProvider.java
+++ b/com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/naming/LocalNamesProvider.java
@@ -14,14 +14,14 @@
 import static org.eclipse.xtext.util.Strings.isEmpty;
 import static org.eclipse.xtext.util.Tuples.pair;
 
-import com.google.eclipse.protobuf.model.util.*;
-import com.google.inject.*;
+import java.util.List;
 
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.xtext.naming.*;
 import org.eclipse.xtext.util.*;
 
-import java.util.List;
+import com.google.eclipse.protobuf.model.util.*;
+import com.google.inject.*;
 
 /**
  * Provides alternative qualified names for protobuf elements.
@@ -50,9 +50,6 @@
  * <li>{@code test.names.Person.PhoneType}</li>
  * </ul>
  * </p>
- * <p>
- * This class provides the non-default qualified names recognized by protoc.
- * </p>
  *
  * @author alruiz@google.com (Alex Ruiz)
  */