A sub-attribute system for constrained markup environments.
The attributes are defined within the title or alt attributes on any element. They are seperated by the ~ character. The section preceding the first ~ is the actual content you want to end up in that attribute. The other are a series of : seperated attribute:value pairs. These will be attached to the same element.
Although you can set the attributes yourself in HTML the place where subttribute really shines is in:
Will eventually set the attributes on the images:
See the example for Jekyll/Markdown (GitHub Pages-style) usage.