Fix doxygen comments.
diff --git a/asio/include/asio/basic_waitable_timer.hpp b/asio/include/asio/basic_waitable_timer.hpp
index 2c77e34..48220e7 100644
--- a/asio/include/asio/basic_waitable_timer.hpp
+++ b/asio/include/asio/basic_waitable_timer.hpp
@@ -40,7 +40,7 @@
  * Most applications will use the asio::waitable_timer typedef.
  *
  * @note This waitable timer functionality is for use with the C++11 standard
- * library's @c <chrono> facility, or with the Boost.Chrono library.
+ * library's @c &lt;chrono&gt; facility, or with the Boost.Chrono library.
  *
  * @par Thread Safety
  * @e Distinct @e objects: Safe.@n
diff --git a/asio/include/asio/high_resolution_timer.hpp b/asio/include/asio/high_resolution_timer.hpp
index 297c383..66b05d1 100644
--- a/asio/include/asio/high_resolution_timer.hpp
+++ b/asio/include/asio/high_resolution_timer.hpp
@@ -34,7 +34,7 @@
 #if defined(GENERATING_DOCUMENTATION)
 /// Typedef for a timer based on the high resolution clock.
 /**
- * This typedef uses the C++11 @c <chrono> standard library facility, if
+ * This typedef uses the C++11 @c &lt;chrono&gt; standard library facility, if
  * available. Otherwise, it may use the Boost.Chrono library. To explicitly
  * utilise Boost.Chrono, use the basic_waitable_timer template directly:
  * @code
diff --git a/asio/include/asio/steady_timer.hpp b/asio/include/asio/steady_timer.hpp
index 6a1f8f6..77d314c 100644
--- a/asio/include/asio/steady_timer.hpp
+++ b/asio/include/asio/steady_timer.hpp
@@ -34,7 +34,7 @@
 #if defined(GENERATING_DOCUMENTATION)
 /// Typedef for a timer based on the steady clock.
 /**
- * This typedef uses the C++11 @c <chrono> standard library facility, if
+ * This typedef uses the C++11 @c &lt;chrono&gt; standard library facility, if
  * available. Otherwise, it may use the Boost.Chrono library. To explicitly
  * utilise Boost.Chrono, use the basic_waitable_timer template directly:
  * @code
diff --git a/asio/include/asio/system_timer.hpp b/asio/include/asio/system_timer.hpp
index 36a06ce..6f73e22 100644
--- a/asio/include/asio/system_timer.hpp
+++ b/asio/include/asio/system_timer.hpp
@@ -34,7 +34,7 @@
 #if defined(GENERATING_DOCUMENTATION)
 /// Typedef for a timer based on the system clock.
 /**
- * This typedef uses the C++11 @c <chrono> standard library facility, if
+ * This typedef uses the C++11 @c &lt;chrono&gt; standard library facility, if
  * available. Otherwise, it may use the Boost.Chrono library. To explicitly
  * utilise Boost.Chrono, use the basic_waitable_timer template directly:
  * @code