I read that as almost English but it could be almost any language.
Without these almost lanugage identifiers, we'd have to type http://74.125.21.113 to visit Google.
I'd never heard the term before this question though, so I wouldn't think it very widespread.
The clue is in the context, where it says
more formally referred to as Uniform Resource Locators (URLs)
a URL looks like this:
http://ell.stackexchange.com/postsa/110494