An Annotation is a piece of information attached to a certain region of a text document. New kinds of annotations may be defined using this extension point. Annotations are attached to documents via their annotation model and may be displayed in text editors and views. Annotation types form a hierarchy: an annotation type may refine another type by specifying it in its <code>super</code> attribute. Some annotations serve as the UI counterpart of markers (see <code>org.eclipse.core.resources.IMarker</code>), while others exist on their own without having a persistable form. The mapping between markers and annotation types is defined by the optional <code>markerType</code> attribute. A marker type definition. The unique name of this annotation type. The marker type that this annotation type corresponds to, if any. The name of the parent type, if this type is a descendant of another annotation type. The severity of this annotation type, used for ordering. Any out of 1, 2, 3. 3.0 This is an excerpt from the plugin.xml for JDT UI, which adds the java compiler error and warning annotations: <extension point="org.eclipse.ui.editors.annotationTypes"> <type name="org.eclipse.jdt.ui.error" super="org.eclipse.ui.workbench.texteditor.error" markerType="org.eclipse.jdt.core.problem" markerSeverity="2"> </type> <type name="org.eclipse.jdt.ui.warning" super="org.eclipse.ui.workbench.texteditor.warning" markerType="org.eclipse.jdt.core.problem" markerSeverity="1"> </type> <type name="org.eclipse.jdt.ui.info" super="org.eclipse.ui.workbench.texteditor.info" markerType="org.eclipse.jdt.core.problem" markerSeverity="0"> </type> </extension> See the org.eclipse.jface.text.source.Annotation class and the org.eclipse.ui.editors.markerAnnotationSpecification extension point. Copyright (c) 2001, 2004 IBM Corporation and others.<br> All rights reserved. This program and the accompanying materials are made available under the terms of the Common Public License v1.0 which accompanies this distribution, and is available at <a href="http://www.eclipse.org/legal/cpl-v10.html">http://www.eclipse.org/legal/cpl-v10.html</a>