Hotlinking refers to embedding images which are hosted by someone else's webspace and not your own. From the board FAQ
Plus, you should only include an inline images from web space that you own, or with the permission from the webmaster on which the image is located to avoid what results in costly bandwidth theft to the originating site owner.
Instead, please post a link to the image.
It's a rule not commonly known to new users so I just thought I would point it out.