Glossary ========== .. glossary:: RSS **RSS** *(Really Simple Syndication)* is a web feed format that is used to publish frequently updated content, like news articles, blog posts, etc. It is a format that is particularly suited to being read by computers, and is therefore the preferred way of getting content from the web into an e-book. There are many other feed formats in use on the Internet, and calibre understands most of them. In particular, it has good support for the *ATOM* format, which is commonly used for blogs. recipe A recipe is a set of instructions that teach calibre how to convert an online news source, such as a magazine or a blog, into an e-book. A recipe is essentially `Python `_ code. As such, it is capable of converting arbitrarily complex news sources into e-books. At the simplest level, it is just a set of variables, such as URLs, that give calibre enough information to go out onto the Internet and download the news. HTML **HTML** *(Hyper Text Mark-Up Language)*, a subset of Standard Generalized Mark-Up Language (SGML) for electronic publishing, is the specific standard used for the World Wide Web. CSS **CSS** *(Cascading Style Sheets)* is a language used to describe how an :term:`HTML` document should be rendered (visual styling). API **API** *(Application Programming Interface)* is a source code interface that a library provides to support requests for services to be made of it by computer programs. LRF **LRF** The e-book format that is read by the SONY e-book readers. URL **URL** *(Uniform Resource Locator)* for example: ``http://example.com`` regexp **Regular expressions** provide a concise and flexible means for identifying strings of text of interest, such as particular characters, words, or patterns of characters. See :doc:`the tutorial ` for an introduction to regular expressions.