How would you tackle declaring numerous images in a DTD? Would you have to specifiy every single image being used in the XML or is there way to specify it in a more efficient way?

For example, if I was to create a directory of businesses and wanted each business to have their own logo.

Each logo would be a link to the image in some tags:
Code:
<business>
...
<logo>http://site.com/img/company1.jpeg</logo>
...
</business>
<business>
...
<logo>http://site.com/img/company2.jpeg</logo>
...
</business>
Any thoughts?

Thanks.