--- /dev/null
+# declaration-colon-space-before
+
+Require a single space or disallow whitespace before the colon of declarations.
+
+```css
+a { color :pink }
+/** ↑
+ * The space before this colon */
+```
+
+## Options
+
+`string`: `"always"|"never"`
+
+### `"always"`
+
+There *must always* be a single space before the colon.
+
+The following patterns are considered violations:
+
+```css
+a { color: pink }
+```
+
+```css
+a { color:pink }
+```
+
+The following patterns are *not* considered violations:
+
+```css
+a { color : pink }
+```
+
+```css
+a { color :pink }
+```
+
+### `"never"`
+
+There *must never* be whitespace before the colon.
+
+The following patterns are considered violations:
+
+```css
+a { color : pink }
+```
+
+```css
+a { color :pink }
+```
+
+The following patterns are *not* considered violations:
+
+```css
+a { color: pink }
+```
+
+```css
+a { color:pink }
+```