diff --git a/core/java/android/provider/CallLog.java b/core/java/android/provider/CallLog.java
index fbd61cf3f4129..c7c6ceb5c16d5 100644
--- a/core/java/android/provider/CallLog.java
+++ b/core/java/android/provider/CallLog.java
@@ -284,8 +284,10 @@ public class CallLog {
 
         /**
          * The cached name associated with the phone number, if it exists.
-         * This value is not guaranteed to be current, if the contact information
-         * associated with this number has changed.
+         *
+         * <p>This value is typically filled in by the dialer app for the caching purpose,
+         * so it's not guaranteed to be present, and may not be current if the contact
+         * information associated with this number has changed.
          * <P>Type: TEXT</P>
          */
         public static final String CACHED_NAME = "name";
@@ -293,8 +295,10 @@ public class CallLog {
         /**
          * The cached number type (Home, Work, etc) associated with the
          * phone number, if it exists.
-         * This value is not guaranteed to be current, if the contact information
-         * associated with this number has changed.
+         *
+         * <p>This value is typically filled in by the dialer app for the caching purpose,
+         * so it's not guaranteed to be present, and may not be current if the contact
+         * information associated with this number has changed.
          * <P>Type: INTEGER</P>
          */
         public static final String CACHED_NUMBER_TYPE = "numbertype";
@@ -302,8 +306,10 @@ public class CallLog {
         /**
          * The cached number label, for a custom number type, associated with the
          * phone number, if it exists.
-         * This value is not guaranteed to be current, if the contact information
-         * associated with this number has changed.
+         *
+         * <p>This value is typically filled in by the dialer app for the caching purpose,
+         * so it's not guaranteed to be present, and may not be current if the contact
+         * information associated with this number has changed.
          * <P>Type: TEXT</P>
          */
         public static final String CACHED_NUMBER_LABEL = "numberlabel";
@@ -339,40 +345,50 @@ public class CallLog {
 
         /**
          * The cached URI to look up the contact associated with the phone number, if it exists.
-         * This value may not be current if the contact information associated with this number
-         * has changed.
+         *
+         * <p>This value is typically filled in by the dialer app for the caching purpose,
+         * so it's not guaranteed to be present, and may not be current if the contact
+         * information associated with this number has changed.
          * <P>Type: TEXT</P>
          */
         public static final String CACHED_LOOKUP_URI = "lookup_uri";
 
         /**
          * The cached phone number of the contact which matches this entry, if it exists.
-         * This value may not be current if the contact information associated with this number
-         * has changed.
+         *
+         * <p>This value is typically filled in by the dialer app for the caching purpose,
+         * so it's not guaranteed to be present, and may not be current if the contact
+         * information associated with this number has changed.
          * <P>Type: TEXT</P>
          */
         public static final String CACHED_MATCHED_NUMBER = "matched_number";
 
         /**
          * The cached normalized(E164) version of the phone number, if it exists.
-         * This value may not be current if the contact information associated with this number
-         * has changed.
+         *
+         * <p>This value is typically filled in by the dialer app for the caching purpose,
+         * so it's not guaranteed to be present, and may not be current if the contact
+         * information associated with this number has changed.
          * <P>Type: TEXT</P>
          */
         public static final String CACHED_NORMALIZED_NUMBER = "normalized_number";
 
         /**
          * The cached photo id of the picture associated with the phone number, if it exists.
-         * This value may not be current if the contact information associated with this number
-         * has changed.
+         *
+         * <p>This value is typically filled in by the dialer app for the caching purpose,
+         * so it's not guaranteed to be present, and may not be current if the contact
+         * information associated with this number has changed.
          * <P>Type: INTEGER (long)</P>
          */
         public static final String CACHED_PHOTO_ID = "photo_id";
 
         /**
          * The cached photo URI of the picture associated with the phone number, if it exists.
-         * This value may not be current if the contact information associated with this number
-         * has changed.
+         *
+         * <p>This value is typically filled in by the dialer app for the caching purpose,
+         * so it's not guaranteed to be present, and may not be current if the contact
+         * information associated with this number has changed.
          * <P>Type: TEXT (URI)</P>
          */
         public static final String CACHED_PHOTO_URI = "photo_uri";
@@ -380,9 +396,10 @@ public class CallLog {
         /**
          * The cached phone number, formatted with formatting rules based on the country the
          * user was in when the call was made or received.
-         * This value is not guaranteed to be present, and may not be current if the contact
-         * information associated with this number
-         * has changed.
+         *
+         * <p>This value is typically filled in by the dialer app for the caching purpose,
+         * so it's not guaranteed to be present, and may not be current if the contact
+         * information associated with this number has changed.
          * <P>Type: TEXT</P>
          */
         public static final String CACHED_FORMATTED_NUMBER = "formatted_number";
diff --git a/core/java/android/provider/ContactsContract.java b/core/java/android/provider/ContactsContract.java
index c70304e140cff..c495e6c163ac6 100644
--- a/core/java/android/provider/ContactsContract.java
+++ b/core/java/android/provider/ContactsContract.java
@@ -35,6 +35,7 @@ import android.content.Intent;
 import android.content.res.AssetFileDescriptor;
 import android.content.res.Resources;
 import android.database.Cursor;
+import android.database.CursorWrapper;
 import android.database.DatabaseUtils;
 import android.graphics.Rect;
 import android.net.Uri;
@@ -138,8 +139,20 @@ public final class ContactsContract {
     public static final String DIRECTORY_PARAM_KEY = "directory";
 
     /**
-     * A query parameter that limits the number of results returned. The
+     * A query parameter that limits the number of results returned for supported URIs. The
      * parameter value should be an integer.
+     *
+     * <p>This parameter is not supported by all URIs.  Supported URIs include, but not limited to,
+     * {@link Contacts#CONTENT_URI},
+     * {@link RawContacts#CONTENT_URI},
+     * {@link Data#CONTENT_URI},
+     * {@link CommonDataKinds.Phone#CONTENT_URI},
+     * {@link CommonDataKinds.Callable#CONTENT_URI},
+     * {@link CommonDataKinds.Email#CONTENT_URI},
+     * {@link CommonDataKinds.Contactables#CONTENT_URI},
+     *
+     * <p>In order to limit the number of rows returned by a non-supported URI, you can implement a
+     * {@link CursorWrapper} and override the {@link CursorWrapper#getCount()} methods.
      */
     public static final String LIMIT_PARAM_KEY = "limit";
 
@@ -437,6 +450,9 @@ public final class ContactsContract {
 
         /**
          * _ID of the default directory, which represents locally stored contacts.
+         * <b>This is only supported by {@link ContactsContract.Contacts#CONTENT_URI} and
+         * {@link ContactsContract.Contacts#CONTENT_FILTER_URI}.
+         * Other URLs do not support the concept of "visible" or "invisible" contacts.
          */
         public static final long DEFAULT = 0;