[err4nt]

I get the concept of using multiple classes to modify a base style (class="btn btn-small") and even using delimiters in multi-part classnames so you can use regular expressions in your CSS to select groups of classes that conform to a naming convention (I.e. [class^="btn-"] {color:red} would make both class="btn-small" and class="btn-large" red).

What is the advantage to a double delimiter over using a single delimiter? (btn--small)

[lowboy]

.multi-word-block__with-an-element--and-modifier

Also see the .site-search example here http://csswizardry.com/2013/01/mindbemding-getting-your-head...

[err4nt]

Ahh gotcha! I still don't see why they can't do this without doubling up the delimiters just by agreeing on a stricter naming convention ;)