A Namespace is a division in RationalWiki thatdefines and separates content. Except for "main", articles in them are distinguished by having the namespace and a colon before the title, like Essay:Gender and Sysops.
Here are the namespace definitions in RationalWiki:
|Main||This is where "mission" articles go. Referred to as "Mainspace".|
|User||An editor's own space to treat or ignore as they wish. (obscenities/racial/homophobic/nasty entries/redlinks may be censored/amended).|
|RationalWiki||This is info at a "meta" level about the running of the wiki. It also contains the Saloon Bar and Non-CP WIGOs, as well as the timeline and articles related to the history of the site.|
|File (formerly "Image")||This is where pretty pictures or any non-text files are stored.|
|Media||This is not a true namespace, but a way to link directly to a file. For example, Media:Jellybrain.png links directly to the image, whereas File:Jellybrain.png links to its description page.|
|MediaWiki||Technical stuff that relates to the running of the software behind RationalWiki. Things such as the notices which automatically display are held in this space. Only editable by members of the Tech user group.|
|Template||This is a "storage area" for things that are likely to be used on more than one page. See: Help:Templates|
|Help||Here we are.|
|Category||Any article or page can and should be classified into at least one category, this enables searching & identifying subjects much easier.|
|Thread and Summary||The two namespaces used by the LiquidThreads extension.|
|Conservapedia||Anything about Conservapedia goes in here. It has its own namespace to keep it from accidentally spilling over into the rest of RationalWiki.|
|Essay||A place for individual and original contributions which allow personal Point Of View or more specialised subjects to be edited by specified editor(s) without interference. However, we do request that essays have some tact as these essays will still be associated with RW.|
|Debate||For some reason this namespace is not very well used. The function is largely usurped by talk pages.|
|Fun||Totally off mission and amusing or entertaining? Then it goes here. Don't expect the humour to be too high brow. Is mostly defunct, and is rarely edited these days.|
|Recipe||RationalWiki's concession to weirdness. Mostly defunct.|
|Forum||The namespace for our pure-discussion pages. No one uses them anymore, but the archives are available. Most discussion takes place on individual article pages and the saloon bar.|
|Draft||Used to collaboratively write articles before they are mainspace-worthy.|
|Gadget and Gadget definition||Code for the various tools that can be enabled via your preferences.|
|Special||This is one of two namespaces that are not directly editable, but give you information about the wiki like Recent Changes and user contributions. (The other is the unused "media" namespace.)|
Every page in all of these namespaces (except "special" and "media") has an associated Talk page. Talk pages are not the property of any editor and entries should not be deleted except to archive. In particular it should be noted that an editor's "Talk Page" is not the property of that editor and he or she has no exceptional rights over the contents beyond what is prescribed in the Community Standards.
When you use the "search" box on the left of the page, it will first search only in "main", (unless you have changed the criteria in "your preferences") but will then give you the option to check off boxes for any other namespaces (or their talk spaces) to run the search again.