Editing Astrophysics Data System (section)

===Title and abstract searches===
The search engine first filters search terms in several ways. An M followed by a space or [[hyphen]] has the space or hyphen removed, so that searching for [[Messier catalogue]] objects is simplified and a user input of M45, M 45 or M-45 all result in the same query being executed; similarly, [[New General Catalogue|NGC]] designations and common search terms such as [[Comet Shoemaker-Levy 9|Shoemaker Levy]] and [[T Tauri star|T Tauri]] are stripped of spaces. Unimportant words such as AT, OR and TO are stripped out, although in some cases [[case sensitivity]] is maintained, so that while '''a'''nd is ignored, '''A'''nd is converted to "[[Andromeda (constellation)|Andromeda]]", and '''H'''er is converted to "[[Hercules (constellation)|Hercules]]", but '''h'''er is ignored.<ref>{{cite web |url=http://doc.adsabs.harvard.edu/abs_doc/help_pages/search.html#Stop_Words |title=SAO/NASA ADS HELP: Abstract Query Form |at=2.2.1.2 - Stop Words |publisher=Harvard-Smithsonian Center for Astrophysics |access-date=30 October 2008 |archiveurl=https://web.archive.org/web/20080509091500/http://doc.adsabs.harvard.edu/abs_doc/help_pages/search.html#Stop_Words |archive-date=9 May 2008}}</ref>