diff --git a/src/validate/formatter/MultiDimension.js b/src/validate/formatter/MultiDimension.js
new file mode 100644
index 0000000..e3d2f5c
--- /dev/null
+++ b/src/validate/formatter/MultiDimension.js
@@ -0,0 +1,116 @@
+/**
+ * Multi-dimensional array formatting
+ *
+ *  Copyright (C) 2016 LoVullo Associates, Inc.
+ *
+ *  This file is part of liza.
+ *
+ *  liza is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+var Trait              = require( 'easejs' ).Trait,
+    ValidatorFormatter = require( '../ValidatorFormatter' );
+
+
+/**
+ * Applies supertype for each item in a vector
+ */
+module.exports = Trait( 'MultiDimension' )
+    .implement( ValidatorFormatter )
+    .extend(
+{
+    /**
+     * Delimiter to combine values
+     * @type {string}
+     */
+    'private _delim': '',
+
+
+    /**
+     * Initialize delimiter for parsing and retrieval
+     *
+     * DELIM will be used to split during parsing, and will be used to
+     * join formatted strings during retrieval.
+     *
+     * @param {string} delim delimiter
+     */
+    __mixin: function( delim )
+    {
+        this._delim = ''+delim;
+    },
+
+
+    /**
+     * Parse each item into a vector
+     *
+     * @param {string} data data to parse
+     *
+     * @return {Array} vector of data formatted for storage
+     */
+    'virtual abstract override public parse': function( data )
+    {
+        var split = data.split( this._delim );
+
+        // maintain ES3 compatibility (no map)
+        for ( var i = 0; i < split.length; i++ )
+        {
+            split[ i ] = this.__super( split[ i ] );
+        }
+
+        return split;
+    },
+
+
+    /**
+     * Join formatted vector elements into a delimited string
+     *
+     * If DATA is not a vector, it will be treated as though it were a
+     * vector with a single element `[DATA]'.
+     *
+     * If all elements of DATA are the same value, then only that
+     * value will be returned; there will be no delimiters.  This
+     * might be problematic if #parse is subsequently used, since that
+     * would change the number of elements in the vector.
+     *
+     * @param {Array|string} data vector to parse
+     *
+     * @return {string} delimited string
+     */
+    'virtual abstract override public retrieve': function( data )
+    {
+        // pretend non-arrays are single-element vectors
+        if ( Object.prototype.toString.call( data ) !== '[object Array]' )
+        {
+            return this.__super( data );
+        }
+
+        var parsed = [],
+            same   = true;
+
+        // must maintain ES3 support; no forEach
+        for ( var i = 0; i < data.length; i++ )
+        {
+            parsed[ i ] = this.__super( data[ i ] );
+
+            same = same && (
+                ( i === 0 )
+                || ( parsed[ i - 1 ] === parsed[ i ] )
+            );
+        }
+
+        return ( same )
+             ? parsed[ 0 ]
+             : parsed.join( this._delim );
+    }
+} );
diff --git a/test/validate/formatter/MultiDimensionTest.js b/test/validate/formatter/MultiDimensionTest.js
new file mode 100644
index 0000000..0f700ac
--- /dev/null
+++ b/test/validate/formatter/MultiDimensionTest.js
@@ -0,0 +1,109 @@
+/**
+ * Multi-dimensional array formatting test
+ *
+ *  Copyright (C) 2016 LoVullo Associates, Inc.
+ *
+ *  This file is part of liza.
+ *
+ *  liza is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+var Class              = require( 'easejs' ).Class,
+    liza               = require( '../../../' ),
+    formatter          = liza.validate.formatter,
+    Sut                = formatter.MultiDimension,
+    EchoFormatter      = formatter.EchoFormatter,
+    ValidatorFormatter = liza.validate.ValidatorFormatter,
+    common             = require( './common' ),
+    expect             = require( 'chai' ).expect;
+
+var DummyFormatter = Class.implement( ValidatorFormatter )
+    .extend(
+{
+    'virtual parse': function( data )
+    {
+        return '+' + data;
+    },
+
+    'virtual retrieve': function( data )
+    {
+        return '-' + data;
+    },
+} );
+
+
+describe( 'validate.formatter.MultiDimension', function()
+{
+    describe( '#parse', function()
+    {
+        it( 'splits on delimiter into vector', function()
+        {
+            expect(
+                DummyFormatter.use( Sut( '||' ) )()
+                    .parse( 'foo||bar||baz' )
+            ).to.deep.equal( [ '+foo', '+bar', '+baz' ] );
+        } );
+
+
+        it( 'produces vector for non-delimited strings', function()
+        {
+            expect(
+                DummyFormatter.use( Sut( '||' ) )()
+                    .parse( 'foo' )
+            ).to.deep.equal( [ '+foo' ] );
+        } );
+    } );
+
+
+    describe( '#retrieve', function()
+    {
+        it( 'applies formatting to each element in vector', function()
+        {
+            expect(
+                DummyFormatter.use( Sut( '||' ) )()
+                    .retrieve( [ 'one', 'two', 'three' ] )
+            ).to.equal( '-one||-two||-three' );
+        } );
+
+
+        it( 'treats scalars as single-element vectors', function()
+        {
+            expect(
+                DummyFormatter.use( Sut( '||' ) )()
+                    .retrieve( 'one' )
+            ).to.equal( '-one' );
+        } );
+
+
+        describe( 'given identical elements', function()
+        {
+            it( 'combines if all elements are identical', function()
+            {
+                expect(
+                    DummyFormatter.use( Sut( '||' ) )()
+                        .retrieve( [ 'foo', 'foo', 'foo' ] )
+                ).to.equal( '-foo' );
+            } );
+
+
+            it( 'does not combine if not all are identical', function()
+            {
+                expect(
+                    DummyFormatter.use( Sut( '||' ) )()
+                        .retrieve( [ 'foo', 'foo', 'bar' ] )
+                ).to.equal( '-foo||-foo||-bar' );
+            } );
+        } );
+    } );
+} );