When should one use HTML entities?

Based on the comments I have received, I looked into this a little further. It seems that currently the best practice is to forgo using HTML entities and use the actual UTF-8 character instead. The reasons listed are as follows:

1. UTF-8 encodings are easier to read and edit for those who understand what the character means and know how to type it.
2. UTF-8 encodings are just as unintelligible as HTML entity encodings for those who don't understand them, but they have the advantage of rendering as special characters rather than hard to understand decimal or hex encodings.

As long as your page's encoding is properly set to UTF-8, you should use the actual character instead of an HTML entity. I read several documents about this topic, but the most helpful were:

• UTF-8: The Secret of Character Encoding
• Wikipedia Special Characters Help

From the UTF-8: The Secret of Character Encoding article:

Wikipedia is a great case study for an application that originally used ISO-8859-1 but switched to UTF-8 when it became far too cumbersome to support foreign languages. Bots will now actually go through articles and convert character entities to their corresponding real characters for the sake of user-friendliness and searchability.

That article also gives a nice example involving Chinese encoding. Here is the abbreviated example for the sake of laziness:

UTF-8:

這兩個字是甚麼意思

HTML Entities:

這兩個字是甚麼意思

The UTF-8 and HTML entity encodings are both meaningle