The SharePoint default master page containes 32 different content placeholders used by the content pages throughout SharePoint sites. Not all of the 32 place holders are required in all custom master pages. In fact, the 8 provided master pages for publishing sites only contains 21 of 32 and one additional content place holder. They areOSSConsole PlaceHolderAdditionalyPageHead PlaceHolderBodyAreaClass PlaceHolderBodyLeftBorder PlaceHolderBodyRightMargin PlaceHolderCalendarNavigator PlaceHolderLeftActions PlaceHolderNavBar PlaceHolderLeftNavBarTop PlaceHolderMain PlaceHolderMiniConsole PlaceHolderNavSpacer PlaceHolderPageDescription PlaceHolderPageImage PlaceHolderPageTitle PlaceHolderTitleInTitleArea PlaceHolderSearchArea PlaceHolderTitleAreaClass PlaceHolderTitleAreaSeparator PlaceHolderTitleBreadcrumb PlaceHolderTtileLeftBorder PlaceHolderTitleRightMargin
Some of the content placeholders listed in the preceding table, while included in the eight publishing master pages, are never rendered and shown, This is done by placing the content holders within ASP.NET panel and set the visibility to false. This technique enables site developers and site designers to include content placeholders that are included within content pages, but keep any of the content defined in the content pages from being rendered. This is a common re factoring technique when implementing a rebrading compain on a site. It enables designers to hide content placeholders with one simple action in the master page without going through all content pages to remove the content placeholder.