This is going to be one of those posts some people brush aside saying "duh, I've known that" but for others will be the "ah, finally!" reaction they've been looking for. Nothing epic here...

I frequently get a question that comes in one of two flavors:

• Why can't I create Blogs, Wikis, Team Sites or Blank Sites in my Publishing site collection (created with the Publishing Portal site template)?
• Why can I only create certain pages in the Search Center site in my Publishing site?

To cut to the chase, you actually can do this. What the SharePoint team did was provide a way for us to filter what site templates are available to use when creating subsites within specific sites as well as filter which page layouts are available on a site by site basis when our content owners create pages. Out of the box, site collections created using the Publishing Portal site template can only contain other sites created using the Publishing Site or Publishing Site with Workflow site templates. This filtering is implemented by the Publishing site definition. However it is very easy to change.

Go into any Publishing site's Site Settings page and look under the Look & Feel column for the Page Layouts & Site Templates link. From this page you'll be able to do the following:

• Inherit the parent site's settings for site templates & page layouts.
• Turn off all filtering for the site templates & page layouts that are available to content owners and hierarchy managers (those who can create subsites... aka: manage the site topology).
• Turn on filtering and customize the site templates & page layouts that are available to content owners and hierarchy managers.

It's quite interesting how this little link has been staring so many people in the face, but they just didn't realize what it did. Sounds like a good case to be renamed in SharePoint vNext eh? Discoverable... yet the crux reason why the Office team went with the Ribbon: stuff was too hard to find among Word's 1,300+ commands! I've even had people come up to me at conferences wanting to share the code they wrote that modifies the filter... they are so proud to say it only took 3 hours to write, test and perfect! I feel so bad when I show them it's just a handful of clicks... no code.

So why does this capability even exist? Great question, you sitting there sipping your coffee. Consider a multilingual solution; this capability gives designers & developers the capability to create page rendering options (aka: page layouts) for the same content type, but for different locale. Maybe the English version of a page should be rendered differently than, say, a Hebrew or Arabic version (which reads right-to-left vs. left-to-right).

Hope this helps someone in the future!