Several aspects of Memory Alpha set it apart from other reference works, such as its method of citing sources. All information must be cited from a valid source (see Canon section below), but rather than a "Works Cited" or "References" list, Memory Alpha prefers stand-alone inline citations, which are placed in parentheses after the sentence or section in question. For television episodes, this consists of an abbreviation for the series from which the information came (e.g. DS9 for '), followed by the name of the episode in double quotation marks. So, to cite information from the ' (TNG) pilot "Encounter at Farpoint", one would add: (TNG: "Encounter at Farpoint"). The same rule applies for films, without the series prefix and with italics in place of quotation marks. The same method of notation is also used in the printed "Star Trek Encyclopedia", which is unrelated to the Memory Alpha wiki.