diff --git a/libstring/string.h b/libstring/string.h
index 3ab38ca..37406b5 100644
--- a/libstring/string.h
+++ b/libstring/string.h
@@ -4,10 +4,19 @@
 #include <stddef.h>
 #include <stdint.h>
 
+/* Set block of memory */
 size_t memset (void* dst, uint8_t b, size_t n);
+
+/* Copy memory from src to dst */
 size_t memcpy (void* dst, const void* src, size_t n);
+
+/* Copy n chars from string */
 void strncpy (char* dst, const char* src, size_t n);
+
+/* Count chars in a string */
 size_t strlen (const char* str);
+
+/* Compare blocks of memory */
 int memcmp (const void* s1, const void* s2, size_t n);
 
 #endif // _LIBSTRING_STRING_H