diff --git a/README.md b/README.md
index a55aa53..296ddc6 100644
--- a/README.md
+++ b/README.md
@@ -991,6 +991,7 @@ Defaults:
   $data:            false,
   allErrors:        false,
   verbose:          false,
+  $comment:         false, // NEW in Ajv version 6.0
   jsonPointers:     false,
   uniqueItems:      true,
   unicode:          true,
@@ -1032,6 +1033,10 @@ Defaults:
 - _$data_: support [$data references](#data-reference). Draft 6 meta-schema that is added by default will be extended to allow them. If you want to use another meta-schema you need to use $dataMetaSchema method to add support for $data reference. See [API](#api).
 - _allErrors_: check all rules collecting all errors. Default is to return after the first error.
 - _verbose_: include the reference to the part of the schema (`schema` and `parentSchema`) and validated data in errors (false by default).
+- _$comment_ (NEW in Ajv version 6.0): log or pass the value of `$comment` keyword to a function. Option values:
+  - `false` (default): ignore $comment keyword.
+  - `true`: log the keyword value to console.
+  - function: pass the keyword value, its schema path and root schema to the specified function
 - _jsonPointers_: set `dataPath` property of errors using [JSON Pointers](https://tools.ietf.org/html/rfc6901) instead of JavaScript property access notation.
 - _uniqueItems_: validate `uniqueItems` keyword (true by default).
 - _unicode_: calculate correct length of strings with unicode pairs (true by default). Pass `false` to use `.length` of strings that is faster, but gives "incorrect" lengths of strings with unicode pairs - each unicode pair is counted as two characters.
diff --git a/lib/compile/rules.js b/lib/compile/rules.js
index 0f53db7..5050882 100644
--- a/lib/compile/rules.js
+++ b/lib/compile/rules.js
@@ -18,10 +18,11 @@ module.exports = function rules() {
     { rules: [ '$ref', 'const', 'enum', 'not', 'anyOf', 'oneOf', 'allOf', 'if' ] }
   ];
 
-  var ALL = [ 'type' ];
+  var ALL = [ 'type', '$comment' ];
   var KEYWORDS = [
-    '$schema', '$id', 'id', '$comment',
-    'title', 'description', 'default', 'definitions',
+    '$schema', '$id', 'id',
+    'title', 'description',
+    'default', 'definitions',
     'additionalItems', 'then', 'else'
   ];
   var TYPES = [ 'number', 'integer', 'string', 'array', 'object', 'boolean', 'null' ];
@@ -49,6 +50,11 @@ module.exports = function rules() {
       return rule;
     });
 
+    RULES.all.$comment = {
+      keyword: '$comment',
+      code: ruleModules.$comment
+    };
+
     if (group.type) RULES.types[group.type] = group;
   });
 
diff --git a/lib/dot/comment.jst b/lib/dot/comment.jst
new file mode 100644
index 0000000..f959150
--- /dev/null
+++ b/lib/dot/comment.jst
@@ -0,0 +1,9 @@
+{{# def.definitions }}
+{{# def.setupKeyword }}
+
+{{ var $comment = it.util.toQuotedString($schema); }}
+{{? it.opts.$comment === true }}
+  console.log({{=$comment}});
+{{?? typeof it.opts.$comment == 'function' }}
+  self._opts.$comment({{=$comment}}, {{=it.util.toQuotedString($errSchemaPath)}}, validate.root.schema);
+{{?}}
diff --git a/lib/dot/validate.jst b/lib/dot/validate.jst
index 3a508c6..43a5edc 100644
--- a/lib/dot/validate.jst
+++ b/lib/dot/validate.jst
@@ -127,6 +127,10 @@
   {{?}}
 {{?}}
 
+{{? it.schema.$comment && it.opts.$comment }}
+  {{= it.RULES.all.$comment.code(it, '$comment') }}
+{{?}}
+
 {{? $typeSchema }}
   {{? it.opts.coerceTypes }}
     {{ var $coerceToTypes = it.util.coerceToTypes(it.opts.coerceTypes, $typeSchema); }}
diff --git a/lib/dotjs/index.js b/lib/dotjs/index.js
index b5531ed..2fb1b00 100644
--- a/lib/dotjs/index.js
+++ b/lib/dotjs/index.js
@@ -5,6 +5,7 @@ module.exports = {
   '$ref': require('./ref'),
   allOf: require('./allOf'),
   anyOf: require('./anyOf'),
+  '$comment': require('./comment'),
   const: require('./const'),
   contains: require('./contains'),
   dependencies: require('./dependencies'),
diff --git a/spec/.eslintrc.yml b/spec/.eslintrc.yml
index d2d4eda..f9c66d5 100644
--- a/spec/.eslintrc.yml
+++ b/spec/.eslintrc.yml
@@ -8,3 +8,4 @@ globals:
   it: false
   before: false
   beforeEach: false
+  afterEach: false
diff --git a/spec/options.spec.js b/spec/options.spec.js
index ac75180..220516e 100644
--- a/spec/options.spec.js
+++ b/spec/options.spec.js
@@ -1219,4 +1219,92 @@ describe('Ajv Options', function () {
       });
     });
   });
+
+
+  describe('$comment', function() {
+    describe('= true', function() {
+      var logCalls, consoleLog;
+
+      beforeEach(function () {
+        consoleLog = console.log;
+        console.log = log;
+      });
+
+      afterEach(function () {
+        console.log = consoleLog;
+      });
+
+      function log() {
+        logCalls.push(Array.prototype.slice.call(arguments));
+      }
+
+      it('should log the text from $comment keyword', function() {
+        var schema = {
+          properties: {
+            foo: {$comment: 'property foo'},
+            bar: {$comment: 'property bar', type: 'integer'}
+          }
+        };
+
+        var ajv = new Ajv({$comment: true});
+        var fullAjv = new Ajv({allErrors: true, $comment: true});
+
+        [ajv, fullAjv].forEach(function (_ajv) {
+          var validate = _ajv.compile(schema);
+
+          test({}, true, []);
+          test({foo: 1}, true, [['property foo']]);
+          test({foo: 1, bar: 2}, true, [['property foo'], ['property bar']]);
+          test({foo: 1, bar: 'baz'}, false, [['property foo'], ['property bar']]);
+
+          function test(data, valid, expectedLogCalls) {
+            logCalls = [];
+            validate(data) .should.equal(valid);
+            logCalls .should.eql(expectedLogCalls);
+          }
+        });
+
+        console.log = consoleLog;
+      });
+    });
+
+    describe('function hook', function() {
+      var hookCalls;
+
+      function hook() {
+        hookCalls.push(Array.prototype.slice.call(arguments));
+      }
+
+      it('should pass the text from $comment keyword to the hook', function() {
+        var schema = {
+          properties: {
+            foo: {$comment: 'property foo'},
+            bar: {$comment: 'property bar', type: 'integer'}
+          }
+        };
+
+        var ajv = new Ajv({$comment: hook});
+        var fullAjv = new Ajv({allErrors: true, $comment: hook});
+
+        [ajv, fullAjv].forEach(function (_ajv) {
+          var validate = _ajv.compile(schema);
+
+          test({}, true, []);
+          test({foo: 1}, true, [['property foo', '#/properties/foo/$comment', schema]]);
+          test({foo: 1, bar: 2}, true,
+            [['property foo', '#/properties/foo/$comment', schema],
+             ['property bar', '#/properties/bar/$comment', schema]]);
+          test({foo: 1, bar: 'baz'}, false,
+            [['property foo', '#/properties/foo/$comment', schema],
+             ['property bar', '#/properties/bar/$comment', schema]]);
+
+          function test(data, valid, expectedHookCalls) {
+            hookCalls = [];
+            validate(data) .should.equal(valid);
+            hookCalls .should.eql(expectedHookCalls);
+          }
+        });
+      });
+    });
+  });
 });
diff --git a/spec/tests/rules/comment.json b/spec/tests/rules/comment.json
new file mode 100644
index 0000000..5be030e
--- /dev/null
+++ b/spec/tests/rules/comment.json
@@ -0,0 +1,40 @@
+[
+  {
+    "description": "$comment keyword",
+    "schema": {
+      "$comment": "test"
+    },
+    "tests": [
+      {
+        "description": "any value is valid",
+        "data": 1,
+        "valid": true
+      }
+    ]
+  },
+  {
+    "description": "$comment keyword in subschemas",
+    "schema": {
+      "type": "object",
+      "properties": {
+        "foo": {
+          "$comment": "test"
+        }
+      }
+    },
+    "tests": [
+      {
+        "description": "empty object is valid",
+        "data": {},
+        "valid": true
+      },
+      {
+        "description": "any value of property foo is valid object is valid",
+        "data": {
+          "foo": 1
+        },
+        "valid": true
+      }
+    ]
+  }
+]