diff --git a/libc/include/netinet/ether.h b/libc/include/netinet/ether.h
index 3e6a4e3..6268a14 100644
--- a/libc/include/netinet/ether.h
+++ b/libc/include/netinet/ether.h
@@ -26,19 +26,56 @@
  * SUCH DAMAGE.
  */
 
-#ifndef _NETINET_ETHER_H_
-#define _NETINET_ETHER_H_ 1
+#pragma once
+
+/**
+ * @file netinet/ether.h
+ * @brief Ethernet (MAC) addresses.
+ */
 
 #include <sys/cdefs.h>
 #include <netinet/if_ether.h>
 
 __BEGIN_DECLS
 
+/**
+ * [ether_ntoa(3)](http://man7.org/linux/man-pages/man3/ether_ntoa.3.html) returns a string
+ * representation of the given Ethernet address.
+ *
+ * Returns a pointer to a static buffer.
+ *
+ * Available since API level 11.
+ */
 char* ether_ntoa(const struct ether_addr* __addr) __INTRODUCED_IN(11);
+
+/**
+ * [ether_ntoa_r(3)](http://man7.org/linux/man-pages/man3/ether_ntoa_r.3.html) returns a string
+ * representation of the given Ethernet address.
+ *
+ * Returns a pointer to the given buffer.
+ *
+ * Available since API level 11.
+ */
 char* ether_ntoa_r(const struct ether_addr* __addr, char* __buf) __INTRODUCED_IN(11);
+
+/**
+ * [ether_aton(3)](http://man7.org/linux/man-pages/man3/ether_aton.3.html) returns an `ether_addr`
+ * corresponding to the given Ethernet address string.
+ *
+ * Returns a pointer to a static buffer, or NULL if the given string isn't a valid MAC address.
+ *
+ * Available since API level 11.
+ */
 struct ether_addr* ether_aton(const char* __ascii) __INTRODUCED_IN(11);
+
+/**
+ * [ether_aton_r(3)](http://man7.org/linux/man-pages/man3/ether_aton_r.3.html) returns an
+ * `ether_addr` corresponding to the given Ethernet address string.
+ *
+ * Returns a pointer to the given buffer, or NULL if the given string isn't a valid MAC address.
+ *
+ * Available since API level 11.
+ */
 struct ether_addr* ether_aton_r(const char* __ascii, struct ether_addr* __addr) __INTRODUCED_IN(11);
 
 __END_DECLS
-
-#endif