notation for referring to the intersection of several subjects; for example, the notation "31:[622+669](485)" refers to the statistics of mining and metallurgy in Sweden. The UDC is an example of an analytico-synthetic classification, i.e., it permits the linking of one concept to another. Although some have described it as faceted, it is not, though there are some faceted elements in it. A truly faceted classification consists solely of simple concepts; there are many compound concepts listed in the UDC. It is still used by many libraries and bibliographic services outside the English-speaking world, and in some non-traditional contexts such as the BBC Archives. Personal difficulties and World War I In 1906, with his father Édouard near death and his businesses falling apart, Paul and his brother and five step-siblings formed a company, ("Otlet Brothers") to try to manage these businesses, which included mines and railways. Paul, though he was consumed with his bibliographic work, became president of the company. In 1907, Édouard died, and the family struggled to maintain all parts of the business. In April 1908, Paul Otlet and his wife began divorce proceedings. Otlet remarried in 1912, to Cato Van Nederhesselt. In 1913, La Fontaine won the Nobel Peace Prize, and invested his winnings into Otlet and La Fontaine's bibliographic ventures, which were suffering from lack of funding. Otlet journeyed to the United States in early 1914 to try to get additional funding from the U.S. Government, but his efforts soon came to a halt due to the outbreak of World War I. Otlet returned to Belgium, but quickly fled after it became occupied by the Germans; he spent the majority of the war in Paris and various cities in Switzerland. Both his sons fought in the Belgian army, and one of them, Jean, died during the war in the Battle of the Yser. Otlet spent much of the war trying to bring about peace, and the creation of multinational institutions that he felt could avert future wars. In 1914, he published a book, "" ("The End of War") that defined a "World Charter of Human Rights" as the basis for an international federation. The Mundaneum In 1910, Otlet and La Fontaine first envisioned a "city of knowledge", which Otlet originally named the "" ("World Palace"), that would serve as a central repository for the world's information. In 1919, soon after the end of World War I, they