diff --git a/README.md b/README.md
index 203e881..31e0460 100644
--- a/README.md
+++ b/README.md
@@ -1,13 +1,15 @@
-webcomponents.js
+webcomponents.js (v1 spec polyfills)
 ================
 
 [![Build Status](https://travis-ci.org/webcomponents/webcomponentsjs.svg?branch=master)](https://travis-ci.org/webcomponents/webcomponentsjs)
 
+> **Note**. For polyfills that work with the older Custom Elements and Shadow DOM v0 specs, see the [master branch](https://github.com/webcomponents/webcomponentsjs/).
+
 A suite of polyfills supporting the [Web Components](http://webcomponents.org) specs:
 
-- **Custom Elements**: allows authors to define their own custom tags ([spec](https://w3c.github.io/webcomponents/spec/custom/)).
-- **HTML Imports**: a way to include and reuse HTML documents via other HTML documents ([spec](https://w3c.github.io/webcomponents/spec/imports/)).
-- **Shadow DOM**: provides encapsulation by hiding DOM subtrees under shadow roots ([spec](https://w3c.github.io/webcomponents/spec/shadow/)).
+- **Custom Elements v1**: allows authors to define their own custom tags ([spec](https://w3c.github.io/webcomponents/spec/custom/), [tutorial](https://developers.google.com/web/fundamentals/getting-started/primers/customelements)).
+- **HTML Imports**: a way to include and reuse HTML documents via other HTML documents ([spec](https://w3c.github.io/webcomponents/spec/imports/), [tutorial](https://www.html5rocks.com/en/tutorials/webcomponents/imports/)).
+- **Shadow DOM v1**: provides encapsulation by hiding DOM subtrees under shadow roots ([spec](https://w3c.github.io/webcomponents/spec/shadow/), [tutorial](https://developers.google.com/web/fundamentals/getting-started/primers/shadowdom)).
 
 For browsers that need it, there are also some minor polyfills included:
 - [`HTMLTemplateElement`](https://github.com/webcomponents/template)
@@ -20,8 +22,8 @@ The polyfills are built (concatenated & minified) into several bundles that targ
 different browsers and spec readiness:
 
 - `webcomponents-hi.js` -- HTML Imports (needed by Safari Tech Preview)
-- `webcomponents-hi-ce.js` -- HTML Imports and Custom Elements (needed by Safari 10)
-- `webcomponents-hi-sd-ce.js` -- HTML Imports, Custom Elements and Shady DOM/CSS (needed by Safari 9, Firefox, Edge)
+- `webcomponents-hi-ce.js` -- HTML Imports and Custom Elements v1 (needed by Safari 10)
+- `webcomponents-hi-sd-ce.js` -- HTML Imports, Custom Elements v1 and Shady DOM/CSS (needed by Safari 9, Firefox, Edge)
 - `webcomponents-sd-ce.js` -- Custom Elements and Shady DOM/CSS (no HTML Imports)
 - `webcomponents-lite.js` -- all of the polyfills: HTML Imports, Custom Elements, Shady DOM/CSS and generic platform polyfills (such as ES6 Promise, Constructable events, etc.) (needed by Internet Explorer 11), and Template (needed by IE 11 and Edge)