diff --git a/lib/rules.js b/lib/rules.js
index c38a1d43..16620dcf 100644
--- a/lib/rules.js
+++ b/lib/rules.js
@@ -85,42 +85,43 @@ function forEachHeading(params, callback) {
 }
 
 // Returns (nested) lists as a flat array (in order)
-function flattenLists(tokens, filterBy) {
-  var lists = [];
-  var stack = [];
-  var current = null;
-  var lastWithMap = { "map": [ 0, 1 ] };
-  tokens.forEach(function forToken(token) {
-    if ((token.type === "bullet_list_open") ||
-        (token.type === "ordered_list_open")) {
-      // Save current context and start a new one
-      stack.push(current);
-      current = {
-        "ordered": (token.type === "ordered_list_open"),
-        "open": token,
-        "items": [],
-        "nesting": stack.length - 1,
-        "lastLineIndex": -1,
-        "insert": lists.length
-      };
-    } else if ((token.type === "bullet_list_close") ||
-               (token.type === "ordered_list_close")) {
-      // Finalize current context and restore previous
-      current.lastLineIndex = lastWithMap.map[1];
-      if ((filterBy === undefined) || (filterBy === current.ordered)) {
+function flattenLists(params) {
+  if (!params.flattenLists) {
+    var lists = [];
+    var stack = [];
+    var current = null;
+    var lastWithMap = { "map": [ 0, 1 ] };
+    params.tokens.forEach(function forToken(token) {
+      if ((token.type === "bullet_list_open") ||
+          (token.type === "ordered_list_open")) {
+        // Save current context and start a new one
+        stack.push(current);
+        current = {
+          "ordered": (token.type === "ordered_list_open"),
+          "open": token,
+          "items": [],
+          "nesting": stack.length - 1,
+          "lastLineIndex": -1,
+          "insert": lists.length
+        };
+      } else if ((token.type === "bullet_list_close") ||
+                 (token.type === "ordered_list_close")) {
+        // Finalize current context and restore previous
+        current.lastLineIndex = lastWithMap.map[1];
         lists.splice(current.insert, 0, current);
         delete current.insert;
+        current = stack.pop();
+      } else if (token.type === "list_item_open") {
+        // Add list item
+        current.items.push(token);
+      } else if (token.map) {
+        // Track last token with map
+        lastWithMap = token;
       }
-      current = stack.pop();
-    } else if (token.type === "list_item_open") {
-      // Add list item
-      current.items.push(token);
-    } else if (token.map) {
-      // Track last token with map
-      lastWithMap = token;
-    }
-  });
-  return lists;
+    });
+    params.flattenLists = lists;
+  }
+  return params.flattenLists;
 }
 
 module.exports = [
@@ -180,15 +181,17 @@ module.exports = [
     "tags": [ "bullet", "ul" ],
     "func": function MD004(params, errors) {
       var style = params.options.style || "consistent";
-      flattenLists(params.tokens, false).forEach(function forList(list) {
-        if (style === "consistent") {
-          style = unorderedListStyleFor(list.items[0]);
-        }
-        list.items.forEach(function forItem(item) {
-          if (unorderedListStyleFor(item) !== style) {
-            errors.push(item.lineNumber);
+      flattenLists(params).forEach(function forList(list) {
+        if (!list.ordered) {
+          if (style === "consistent") {
+            style = unorderedListStyleFor(list.items[0]);
           }
-        });
+          list.items.forEach(function forItem(item) {
+            if (unorderedListStyleFor(item) !== style) {
+              errors.push(item.lineNumber);
+            }
+          });
+        }
       });
     }
   },
@@ -198,7 +201,7 @@ module.exports = [
     "desc": "Inconsistent indentation for list items at the same level",
     "tags": [ "bullet", "ul", "indentation" ],
     "func": function MD005(params, errors) {
-      flattenLists(params.tokens).forEach(function forList(list) {
+      flattenLists(params).forEach(function forList(list) {
         var indent = indentFor(list.items[0]);
         list.items.forEach(function forItem(item) {
           if (indentFor(item) !== indent) {
@@ -214,8 +217,8 @@ module.exports = [
     "desc": "Consider starting bulleted lists at the beginning of the line",
     "tags": [ "bullet", "ul", "indentation" ],
     "func": function MD006(params, errors) {
-      flattenLists(params.tokens, false).forEach(function forList(list) {
-        if (!list.nesting && indentFor(list.open)) {
+      flattenLists(params).forEach(function forList(list) {
+        if (!list.ordered && !list.nesting && indentFor(list.open)) {
           errors.push(list.open.lineNumber);
         }
       });
@@ -229,13 +232,15 @@ module.exports = [
     "func": function MD007(params, errors) {
       var optionsIndent = params.options.indent || 2;
       var prevIndent = 0;
-      flattenLists(params.tokens, false).forEach(function forList(list) {
-        var indent = indentFor(list.open);
-        if ((indent > prevIndent) &&
-            ((indent - prevIndent) !== optionsIndent)) {
-          errors.push(list.open.lineNumber);
+      flattenLists(params).forEach(function forList(list) {
+        if (!list.ordered) {
+          var indent = indentFor(list.open);
+          if ((indent > prevIndent) &&
+              ((indent - prevIndent) !== optionsIndent)) {
+            errors.push(list.open.lineNumber);
+          }
+          prevIndent = indent;
         }
-        prevIndent = indent;
       });
     }
   },
@@ -531,17 +536,19 @@ module.exports = [
     "tags": [ "ol" ],
     "func": function MD029(params, errors) {
       var style = params.options.style || "one";
-      flattenLists(params.tokens, true).forEach(function forList(list) {
-        var number = 1;
-        list.items.forEach(function forItem(item) {
-          var re = new RegExp("^\\s*" + String(number) + "\\.");
-          if (!re.test(item.line)) {
-            errors.push(item.lineNumber);
-          }
-          if (style === "ordered") {
-            number++;
-          }
-        });
+      flattenLists(params).forEach(function forList(list) {
+        if (list.ordered) {
+          var number = 1;
+          list.items.forEach(function forItem(item) {
+            var re = new RegExp("^\\s*" + String(number) + "\\.");
+            if (!re.test(item.line)) {
+              errors.push(item.lineNumber);
+            }
+            if (style === "ordered") {
+              number++;
+            }
+          });
+        }
       });
     }
   },
@@ -555,7 +562,7 @@ module.exports = [
       var olSingle = params.options.ol_single || 1;
       var ulMulti = params.options.ul_multi || 1;
       var olMulti = params.options.ol_multi || 1;
-      flattenLists(params.tokens).forEach(function forList(list) {
+      flattenLists(params).forEach(function forList(list) {
         var lineCount = list.lastLineIndex - list.open.map[0];
         var allSingle = lineCount === list.items.length;
         var expectedSpaces = list.ordered ?