Li Europan lingues is a quotation in Occidental, an international auxiliary language devised by Edgar von Wahl in 1922. It is used in some HTML templates as a fill-in or placeholder text.
One of the most common placeholder texts is lorem ipsum. A similar text of this type is the pangram The quick brown fox jumps over the lazy dog, which is often used in fill-in text and to demonstrate and compare typefaces because it contains all 26 letters of the Latin alphabet.
When used as placeholder text, Li Europan lingues is usually one or two paragraphs and reads as follows:
The text of Li Europan lingues is found in many HTML templates and through copying and uploading of templates this phrase seems to have found its use in many websites.
Don Harlow posted a message to the Auxlang List on 5 August 2006, mentioning its appearance in the "CSS Cookbook" from O'Reilly by Christopher Schmitt, and in templates of webpages which implement CSS. [1]
Don Gasper posted another message to the same list suggesting a possible source:
William Patterson was pleasantly surprised that evening to read about the appearance of his version of Lorem ipsum in the "CSS Cookbook" and quickly confessed. In June 1998, at a time when he was dabbling in Occidental, he had come across the Lorem ipsum text somewhere and learned about its use as a template. As was his wont when learning something new like that, he created a webpage about it. But while warning about the existence of "corrupt" versions, he offered one himself which included some Occidental text, a dash of Esperanto, some variations of his given name, and a little bit of nonsense. In September 2002 he came across a copy of his version on the Web. Curious, he searched for other instances, and found that on 10 September 2002, an AllTheWeb search for the strings "ulliam" and "willum" returned 513 hits; by 10 December 2002, 962; and by 14 October 2003, 2337. (One page which he found particularly amusing was a Swedish translation of his own webpage— Occidental, commentary, page colors, page title "Ailanto : Lorem ipsum" and all!) And now it's in the "CSS Cookbook"!