diff -r 000000000000 -r fb9019fb1bf7 src/net/fortuna/ical4j/util/CompatibilityHints.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/net/fortuna/ical4j/util/CompatibilityHints.java	Tue Feb 10 18:12:00 2015 +0100
@@ -0,0 +1,125 @@
+/**
+ * Copyright (c) 2012, Ben Fortuna
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *  o Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ *  o Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ *  o Neither the name of Ben Fortuna nor the names of any other contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package net.fortuna.ical4j.util;
+
+import java.util.Map;
+
+import edu.emory.mathcs.backport.java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * $Id$
+ * 
+ * Created on 9/03/2006
+ * 
+ * A set of keys used to enable compatibility features.
+ * 
+ * @author Ben Fortuna
+ */
+public final class CompatibilityHints {
+
+    /**
+     * A system property key to enable relaxed unfolding. Relaxed unfolding is enabled by setting this system property
+     * to "true".
+     */
+    public static final String KEY_RELAXED_UNFOLDING = "ical4j.unfolding.relaxed";
+
+    /**
+     * A system property key to enable relaxed parsing. Relaxed parsing is enabled by setting this system property to
+     * "true".
+     */
+    public static final String KEY_RELAXED_PARSING = "ical4j.parsing.relaxed";
+
+    /**
+     * A system property key to enable relaxed validation. Relaxed validation disables validation of certain conformance
+     * rules that many iCalendar implementations do not conform to. Relaxed validation is enabled by setting this system
+     * property to "true".
+     */
+    public static final String KEY_RELAXED_VALIDATION = "ical4j.validation.relaxed";
+
+    /**
+     * A system property key used to enable compatibility with Outlook/Exchange-generated iCalendar files. Outlook
+     * compatibility is enabled by setting this system property to "true".
+     */
+    public static final String KEY_OUTLOOK_COMPATIBILITY = "ical4j.compatibility.outlook";
+
+    /**
+     * A system property key used to enable compatibility with Lotus Notes-generated iCalendar files. Notes
+     * compatibility is enabled by setting this system property to "true".
+     */
+    public static final String KEY_NOTES_COMPATIBILITY = "ical4j.compatibility.notes";
+
+    private static final Map HINTS = new ConcurrentHashMap();
+    // preload known hints from the configurator
+    static {
+        setHintEnabled(KEY_RELAXED_UNFOLDING, "true".equals(Configurator.getProperty(KEY_RELAXED_UNFOLDING)));
+        setHintEnabled(KEY_RELAXED_PARSING, "true".equals(Configurator.getProperty(KEY_RELAXED_PARSING)));
+        setHintEnabled(KEY_RELAXED_VALIDATION, "true".equals(Configurator.getProperty(KEY_RELAXED_VALIDATION)));
+        setHintEnabled(KEY_OUTLOOK_COMPATIBILITY, "true".equals(Configurator.getProperty(KEY_OUTLOOK_COMPATIBILITY)));
+        setHintEnabled(KEY_NOTES_COMPATIBILITY, "true".equals(Configurator.getProperty(KEY_NOTES_COMPATIBILITY)));
+    }
+
+    /**
+     * Constructor made private to enforce static nature.
+     */
+    private CompatibilityHints() {
+    }
+
+    /**
+     * @param key
+     *            a compatibility hint key
+     * @param enabled
+     *            indicates whether to enable or disable the compatibility hint
+     */
+    public static void setHintEnabled(final String key, final boolean enabled) {
+        HINTS.put(key, Boolean.valueOf(enabled));
+    }
+
+    /**
+     * @param key
+     *            a compatibility hint key
+     */
+    public static void clearHintEnabled(final String key) {
+        HINTS.remove(key);
+    }
+
+    /**
+     * @param key
+     *            a compatibility hint key
+     * @return true if the specified compatibility hint is enabled, otherwise false
+     */
+    public static boolean isHintEnabled(final String key) {
+        if (HINTS.get(key) != null) {
+            return ((Boolean) HINTS.get(key)).booleanValue();
+        }
+        return "true".equals(Configurator.getProperty(key));
+    }
+}