enclosure tag is used to have media files pr item in rss feeds, only supported by RSS 2.0(ezcFeed will use link tag for ATOM feeds for these), but RSS 2.0 is default feed type now anyway.

Example:

<enclosure url="http://localhost:81/trunk/var/ezwebin_site/storage/images/company/news/lyon-une-metropole-de-taille-europeenne/890-1-eng-GB/Lyon-une-metropole-de-taille-europeenne.jpg" length="52713" type="image/jpeg"/>

The RSS 2.0 specification does not specify if only one or several enclosure tags are supported pr item, so will only add support for one pr item for now.