Mention the quotes requirement in the docs too
#### Escape SVG
-We use the `escape-svg` function to escape the `<`, `>` and `#` characters for SVG background images. These characters need to be escaped to properly render the background images in IE.
+We use the `escape-svg` function to escape the `<`, `>` and `#` characters for SVG background images. These characters need to be escaped to properly render the background images in IE. When using the `escape-svg` function, data URIs must be quoted.
#### Add and Subtract functions