--- /dev/null
+# number-leading-zero
+
+Require or disallow a leading zero for fractional numbers less than 1.
+
+```css
+a { line-height: 0.5; }
+/** ↑
+ * This leading zero */
+```
+
+The `--fix` option on the [command line](../../../docs/user-guide/cli.md#autofixing-errors) can automatically fix all of the problems reported by this rule.
+
+## Options
+
+`string`: `"always"|"never"`
+
+### `"always"`
+
+There *must always* be a leading zero.
+
+The following patterns are considered violations:
+
+```css
+a { line-height: .5; }
+```
+
+```css
+a { transform: translate(2px, .4px); }
+```
+
+The following patterns are *not* considered violations:
+
+```css
+a { line-height: 0.5; }
+```
+
+```css
+a { transform: translate(2px, 0.4px); }
+```
+
+### `"never"`
+
+There *must never* be a leading zero.
+
+The following patterns are considered violations:
+
+```css
+a { line-height: 0.5; }
+```
+
+```css
+a { transform: translate(2px, 0.4px); }
+```
+
+The following patterns are *not* considered violations:
+
+```css
+a { line-height: .5; }
+```
+
+```css
+a { transform: translate(2px, .4px); }
+```