--- /dev/null
+# property-case
+
+Specify lowercase or uppercase for properties.
+
+```css
+ a { width: 1px; }
+/** ↑
+ * These properties */
+```
+
+## Options
+
+`string`: `"lower"|"upper"`
+
+### `"lower"`
+
+The following patterns are considered violations:
+
+```css
+a {
+ Width: 1px
+}
+```
+
+```css
+a {
+ WIDTH: 1px
+}
+```
+
+```css
+a {
+ widtH: 1px
+}
+```
+
+```css
+a {
+ border-Radius: 5px;
+}
+```
+
+```css
+a {
+ -WEBKIT-animation-duration: 3s;
+}
+```
+
+```css
+@media screen and (orientation: landscape) {
+ WiDtH: 500px;
+}
+```
+
+The following patterns are *not* considered violations:
+
+```css
+a {
+ width: 1px
+}
+```
+
+```css
+a {
+ border-radius: 5px;
+}
+```
+
+```css
+a {
+ -webkit-animation-duration: 3s;
+}
+```
+
+```css
+@media screen and (orientation: landscape) {
+ width: 500px;
+}
+```
+
+### `"upper"`
+
+The following patterns are considered violations:
+
+```css
+a {
+ Width: 1px
+}
+```
+
+```css
+a {
+ width: 1px
+}
+```
+
+```css
+a {
+ widtH: 1px
+}
+```
+
+```css
+a {
+ border-Radius: 5px;
+}
+```
+
+```css
+a {
+ -WEBKIT-animation-duration: 3s;
+}
+```
+
+```css
+@media screen and (orientation: landscape) {
+ WiDtH: 500px;
+}
+```
+
+The following patterns are *not* considered violations:
+
+```css
+a {
+ WIDTH: 1px
+}
+```
+
+```css
+a {
+ BORDER-RADIUS: 5px;
+}
+```
+
+```css
+a {
+ -WEBKIT-ANIMATION-DURATION: 3s;
+}
+```
+
+```css
+@media screen and (orientation: landscape) {
+ WIDTH: 500px;
+}
+```