Adding File Type Icons To SharePoint 2013

This is almost entirely copied from, thank you Alan Richards.  There are some notes worth looking at that are specific to 2013

http://www.edutechnow.com/?p=192

“Adding File Type Icons To SharePoint 2010/2013

When you add documents to SharePoint 2010/2013 document libraries sometimes an icon doesn’t appear in the Type column. While this doesn’t stop the file from opening it does spoil the aesthetics of your site.”

Add The Icon
Find an icon for the application (17 x 17 Pixel gif will do it) and copy it to
..Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\TEMPLATE\IMAGES

Edit XML File

You now need to edit the Docicon.xml file, this can be found in

..Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\TEMPLATE\XML

Navigate to the <ByExtension> section and add an entry for the file extension of the application similar to the one shown below

<Mapping Key=”abc” Value=”abc_icon.gif”>

Restart IIS by opening up a command prompt and using the command iisreset

NOTE

If you have a multiple server farm then you will need to repeat these steps on each of your servers”

SPECIFIC TO 2013:

You’d think that this would be needed in the 15 hive, but in my experience nothing changed until I made these changes in the 14 hive.  Also, watch out when copying the mapping key from anything other than the DOCICON.xml file.  The ” may be a format that the file doesn’t like and it will replace all of your icons with a .