When working with content catalogs, if your visitors use an invalid URL, instead of seeing the Page Not Found page they will see an empty page.
WCM tip #15: Use standard SharePoint SEO fields with catalogs to leverage the standard SharePoint SEO capabilities
When working with content catalogs which are published on the Internet use standard SharePoint SEO fields to add search metadata to your catalog items and optimize them for Internet search engines.
When working with content catalogs use slug as the URL field to optimize the URL of the catalog item for Internet search engines.
WCM tip #5: When using SP2013 SEO features the browser title replaces the contents of the PageTitlePlaceHolder Content Place Holder
When using the new Search Engines Optimization features provided with SharePoint 2013 the browser title for the particular page will replace all contents of the PageTitlePlaceHolder Content Place Holder. This is important to know particularly when building hierarchical titles.