by Jenny Knuth, based on the work of Chris Coyier and Taylor Hunt
A data URI is a nice way to include a web resource without needing to make an HTTP request. Chris Coyier explains the technique nicely in Probably Don't Base64 SVG.
While a PNG might use Base64 encoding, for SVG, there is a better way.
Taylor Hunt's experiments led to this solution for optimizing SVGs in data URIs:
"So the best way of encoding SVG in a data URI is data:image/svg+xml,[actual data]. We don’t need the ;charset=utf-8 parameter (or the invalid ;utf8 parameter…), because URLs are always ASCII."