SharePoint Site or System Master page

Site Master Page vs. System Master Page

I have been scratching my head each time I got to working with the SharePoint 2010 master pages, which one do I need to change on the ChangeSiteMasterpage.aspx, so is the purpose of these two master pages clear to everyone:

After a bit of searching around I managed to find some information by Stefan Goßner Senior Escalation Engineer for SharePoint on the technet blog site that makes some sense.

By default the following rule applies:

  • Site Master Pages: used by all publishing pages – and only by publishing pages
  • System Master Pages: used by everything else including forms and view pages

You can use SharePoint Designer to change the master page assignment for individual pages if required.

If you open a page in SharePoint Designer you can see a MasterPageFile setting which can be modified:

  1. “~masterurl/default.master”: the page will use the system master page
  2. “~masterurl/custom.master”: the page will use the site master page

Going further into the master page issue I also found some information that states there is a third master page the Application.master that is used by by all the pages in the _Layouts virtual directory. These pages are the setup pages.