MOOC Learn HTML5 from W3C – Notes – Introduction

I start a serie of blog posts to share notes I took when I attended the MOOCLearn HTML5 from W3C‘. For this first post, you find the most relevant information given in the introduction part of this online course.


Unicorn is W3C’s unified validator, which helps people improve the quality of their Web pages by performing a variety of checks. Unicorn gathers the results of the popular HTML and CSS validators, as well as other useful services, such as Internationalization, RSS/Atom feeds and http headers.

The w3c cheatsheet

The W3C cheatsheet provides quick access to useful information from a variety of specifications published by W3C. It aims at giving in a very compact and mobile-friendly format a compilation of useful knowledge extracted from W3C specifications, completed by summaries of guidelines developed at W3C, in particular the WCAG2 accessibility guidelines, the Mobile Web Best Practices, and a number of internationalization tips.


The word ‘Internationalization’ is often abbreviated to ‘i18n‘. This is a widely used English abbreviation, derived from the fact that there are 18 letters between the ‘i’ and the ‘n’.

Localization is sometimes written as l10n.


As a content author or developer, you should nowadays always choose the UTF-8 character encoding for your content or data. This Unicode encoding is a good choice because you can use a single encoding to handle pretty much any character you are likely to meet. This greatly simplifies things.

Always declare the encoding of your document using a meta element with a charset attribute:

<!DOCTYPE html>

<html lang=”en”>
<meta charset=”utf-8″/>