http://getbem.com/introduction/
In short, you do things like this:
.form { }
.form--theme-xmas { }
.form--simple { }
.form__input { }
.form__submit { }
.form__submit--disabled { }
Where the prefix __ is an Element and -- is a Modifier.
So, in that example you have the form, the form with Christmas modifier and also a form button that is expected to only happen under forms.
http://getbem.com/introduction/
In short, you do things like this:
.form { }
.form--theme-xmas { }
.form--simple { }
.form__input { }
.form__submit { }
.form__submit--disabled { }
Where the prefix __ is an Element and -- is a Modifier.
So, in that example you have the form, the form with Christmas modifier and also a form button that is expected to only happen under forms.