Merge pull request airbnb#14 from airbnb/variable-naming

Add section about using dash-cased for variable names

.scss-lint.yml

@@ -18,6 +18,13 @@ linters:
   LeadingZero:
     enabled: false
 
+  NameFormat:
+    enabled: true
+
+  PrivateNamingConvention:
+    enabled: true
+    prefix: _
+
   PropertySortOrder:
     enabled: false
 

README.md

@@ -18,6 +18,7 @@
   1. [Sass](#sass)
     - [Syntax](#syntax)
     - [Ordering](#ordering-of-property-declarations)
+    - [Variables](#variables)
     - [Mixins](#mixins)
     - [Extend directive](#extend-directive)
     - [Nested selectors](#nested-selectors)
@@ -240,6 +241,10 @@ Use `0` instead of `none` to specify that a style has no border.
     }
     ```
 
+### Variables
+
+Prefer dash-cased variable names (e.g. `$my-variable`) over camelCased or snake_cased variable names. It is acceptable to prefix variable names that are intended to be used only within the same file with an underscore (e.g. `$_my-variable`).
+
 ### Mixins
 
 Mixins should be used to DRY up your code, add clarity, or abstract complexity--in much the same way as well-named functions. Mixins that accept no arguments can be useful for this, but note that if you are not compressing your payload (e.g. gzip), this may contribute to unnecessary code duplication in the resulting styles.