Including Welcome Pages in the search scope in SharePoint Web Content Management solutions

When using SharePoint search in a Web Content Management (WCM) solution you are very likely to create your scope which will include Publishing Pages only. As other pages like Application Pages and Lists' Forms are not accessible by anonymous visitors you don't want them to appear in the search results on the public site. While creating what I call a 'public scope' is rather straight-forward there is one thing you have to keep in mind to make it work as expected.