diff --git a/component.json b/component.json
index 85fed74..0319536 100644
--- a/component.json
+++ b/component.json
@@ -14,8 +14,10 @@
   ],
   "repository": "wooorm/retext-simplify",
   "dependencies": {
-    "wooorm/nlcst-to-string": "^1.1.0",
+    "sindresorhus/array-differ": "^1.0.0",
     "wooorm/nlcst-search": "^1.0.0",
+    "wooorm/nlcst-to-string": "^1.1.0",
+    "ljharb/object-keys": "^1.0.9",
     "wooorm/quotation": "^1.0.0"
   },
   "scripts": [
diff --git a/index.js b/index.js
index 43c3393..71625e7 100644
--- a/index.js
+++ b/index.js
@@ -14,51 +14,68 @@
  * Dependencies.
  */
 
+var keys = require('object-keys');
+var difference = require('array-differ');
 var nlcstToString = require('nlcst-to-string');
 var quotation = require('quotation');
 var search = require('nlcst-search');
 var patterns = require('./data/index.json');
 
+/*
+ * List of all phrases.
+ */
+
+var list = keys(patterns);
+
 /**
- * Search `tree` for validations.
+ * Attacher.
  *
- * @param {Node} tree - NLCST node.
- * @param {VFile} file - Virtual file.
+ * @param {Retext} processor
+ *   - Instance.
+ * @param {Object?} [options]
+ *   - Configuration.
+ * @param {Array.<string>?} [options.ignore]
+ *   - List of phrases to *not* warn about.
+ * @return {Function} - `transformer`.
  */
-function transformer(tree, file) {
-    search(tree, patterns, function (match, position, parent, phrase) {
-        var pattern = patterns[phrase];
-        var replace = pattern.replace;
-        var value = quotation(nlcstToString(match), '“', '”');
-        var message;
+function attacher(processor, options) {
+    var ignore = (options || {}).ignore || [];
+    var phrases = difference(list, ignore);
 
-        if (pattern.omit && !replace.length) {
-            message = 'Remove ' + value;
-        } else {
-            message = 'Replace ' + value + ' with ' +
-                quotation(replace, '“', '”').join(', ');
+    /**
+     * Search `tree` for validations.
+     *
+     * @param {Node} tree - NLCST node.
+     * @param {VFile} file - Virtual file.
+     */
+    function transformer(tree, file) {
+        search(tree, phrases, function (match, position, parent, phrase) {
+            var pattern = patterns[phrase];
+            var replace = pattern.replace;
+            var value = quotation(nlcstToString(match), '“', '”');
+            var message;
 
-            if (pattern.omit) {
-                message += ', or remove it';
+            if (pattern.omit && !replace.length) {
+                message = 'Remove ' + value;
+            } else {
+                message = 'Replace ' + value + ' with ' +
+                    quotation(replace, '“', '”').join(', ');
+
+                if (pattern.omit) {
+                    message += ', or remove it';
+                }
             }
-        }
 
-        message = file.warn(message, {
-            'start': match[0].position.start,
-            'end': match[match.length - 1].position.end
-        });
+            message = file.warn(message, {
+                'start': match[0].position.start,
+                'end': match[match.length - 1].position.end
+            });
 
-        message.ruleId = phrase;
-        message.source = 'retext-simplify';
-    });
-}
+            message.ruleId = phrase;
+            message.source = 'retext-simplify';
+        });
+    }
 
-/**
- * Attacher.
- *
- * @return {Function} - `transformer`.
- */
-function attacher() {
     return transformer;
 }
 
diff --git a/package.json b/package.json
index 3bb56df..9ae0e1d 100644
--- a/package.json
+++ b/package.json
@@ -23,8 +23,10 @@
   "bugs": "https://github.com/wooorm/retext-simplify/issues",
   "author": "Titus Wormer <tituswormer@gmail.com> (http://wooorm.com)",
   "dependencies": {
-    "nlcst-to-string": "^1.1.0",
+    "array-differ": "^1.0.0",
     "nlcst-search": "^1.0.0",
+    "nlcst-to-string": "^1.1.0",
+    "object-keys": "^1.0.9",
     "quotation": "^1.0.0"
   },
   "devDependencies": {
diff --git a/readme.md b/readme.md
index 1fe1bd7..0de4866 100644
--- a/readme.md
+++ b/readme.md
@@ -44,13 +44,18 @@ Yields:
 
 ## API
 
-### `retext.use(simplify)`
+### `retext.use(simplify[, options])`
 
 Check phrases for simpler alternatives.
 
 **Parameters**
 
-*   `simplify` — This plug-in.
+*   `simplify` — This plug-in;
+
+*   `options` (`Object?`, optional):
+
+    *   `ignore` (`Array.<string>`)
+        — List of phrases to *not* warn about.
 
 ## License
 
diff --git a/test.js b/test.js
index b21a852..144c816 100644
--- a/test.js
+++ b/test.js
@@ -23,6 +23,8 @@ var simplify = require('./');
  */
 
 test('simplify', function (t) {
+    t.plan(4);
+
     retext()
         .use(simplify)
         .process([
@@ -44,5 +46,27 @@ test('simplify', function (t) {
             );
         });
 
-    t.end();
+    retext()
+        .use(simplify, {
+            'ignore': [
+                'utilize'
+            ]
+        })
+        .process([
+            'You can utilize a shorter word.',
+            'Be advised, don’t do this.',
+            'That’s the appropriate thing to do.'
+        ].join('\n'), function (err, file) {
+            t.ifError(err, 'should not fail (#2)');
+
+            t.deepEqual(
+                file.messages.map(String),
+                [
+                    '2:1-2:11: Remove “Be advised”',
+                    '3:12-3:23: Replace “appropriate” with “proper”, ' +
+                    '“right”, or remove it'
+                ],
+                'should not warn for `ignore`d phrases'
+            );
+        });
 });