INFO: The "About:" Protocol in Internet Explorer
Retired KB Content Disclaimer
For example, "about:NavigationFailure" directs Internet Explorer to displaya brief page with more information about why a navigation might have failedand helpful hints for avoiding this error in the future.
Microsoft now supports an about: protocol that works as follows. If youenter a URL "about:example", MSHTML (the HTML parsing and rendering enginefor Internet Explorer 4) looks in the registry under "HKML\SOFTWARE\Microsoft\InternetExplorer\AboutURLs" for an string value named "example" and then loads theURL associated with it. If it cannot find the value "example," it generatesand displays a page "<HTML>example</HTML>."
When resolving "about:<string>" URLs, Internet Explorer will look for astring value with a name that matches <string> under the registry key:
For example, "NavigationFailure" is listed as a value name under theaforementioned registry entry that has a string data value of"res://shdoclc.dll/navcancl.htm" on Internet Explorer 5.
If Internet Explorer does not find a match between <string> and a string value in this location, Internet Explorer will enclose <string> in <HTML> start and end tags and render it as HTML content.
NOTE: Other than the about:URLs included under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\InternetExplorer\AboutURLS, about:URLs serve no purpose. For security reasons, as of the release of Microsoft Internet Explorer 6.0 Service Pack 1, when you resolve "about:<string>" URLs, Internet Explorer causes navigation to fail.
Article ID: 183978 - Last Review: 06/22/2014 18:54:00 - Revision: 4.0
- kbinfo KB183978