transparent border
This tag is for images that have a transparent border. The best ways to tell when this is case is if a character appears to be coming off their image's background and into the surrounding background of the webpage, or if the image's thumbnail and sample image appears to have a black border that disappears when viewing the full image.
The following tags are aliased to this tag: alpha_border (learn more).
This tag implicates border, alpha_channel (learn more).