--- /dev/null
+# selector-pseudo-class-case
+
+Specify lowercase or uppercase for pseudo-class selectors.
+
+```css
+ a:hover {}
+/** ↑
+ * This is pseudo-class selector */
+```
+
+## Options
+
+`string`: `"lower"|"upper"`
+
+### `"lower"`
+
+The following patterns are considered violations:
+
+```css
+a:Hover {}
+```
+
+```css
+a:hOvEr {}
+```
+
+```css
+a:HOVER {}
+```
+
+```css
+:ROOT {}
+```
+
+```css
+:-MS-INPUT-PLACEHOLDER {}
+```
+
+The following patterns are *not* considered violations:
+
+```css
+a:hover {}
+```
+
+```css
+:root {}
+```
+
+```css
+:-ms-input-placeholder {}
+```
+
+### `"upper"`
+
+The following patterns are considered violations:
+
+```css
+a:Hover {}
+```
+
+```css
+a:hOvEr {}
+```
+
+```css
+a:hover {}
+```
+
+```css
+:root {}
+```
+
+```css
+:-ms-input-placeholder {}
+```
+
+The following patterns are *not* considered violations:
+
+```css
+a:HOVER {}
+```
+
+```css
+:ROOT {}
+```
+
+```css
+:-MS-INPUT-PLACEHOLDER {}
+```