Hidden feature in Stylus: Named Parameters

While playing with stylus (v0.31), i noticed that you can name your parameters when calling a function:

/* Define */
myMixin(color, font)
    background-color color
    font-family font

/* Use */
body
    myMixin(color: green, font: helvetica)

This is great for mixins with many parameters and you don't want your users to memorize the order of which they need to be defined.

However, I didn't see this in the documentation. Hopefully this feature will stay in for future releases.