HTML Entities or Decimals

10:05AM — Saturday November 17, 2012.

I had issues with the RSS feed for this site. The feed validator was telling me that using a HTML entity like ‘ was invalid. I don’t know much about XML, but it seemed strange; I had escaped the character; I hadn’t just pasted in a ‘curly’ quotation mark.

Turns out XML doesn’t like some HTML entities. Using ∞ for the infinity symbol isn’t good enough, you need to use the HTML decimal ∞. However, it seems that using & for an ampersand is valid. XML is an indiscriminate beast.

I guess that’s why SmartyPants et al. convert characters to HTML decimals rather than entities; the decimal will always work, the entity won’t.

I’ve updated the character reference table on Style Manual accordingly.