Better references in comments.

diff --git a/clunk.c b/clunk.c
index c5289eb13022689f61373211d4779ff34cbd45fd..c9ad397127453c73b8c117cc34e6013ddc757583 100644 (file)
--- a/clunk.c
+++ b/clunk.c
@@ -5,7 +5,10 @@
 #include <unistd.h>
 
 /*
- * Post Office specification 479B requires a pulse length of 200-500 ms.
+ * Post Office Specification PR 479C requires a pulse length of
+ * 200-500 ms.
+ *
+ * <http://gpoclocksystems.byethost22.com/pages/pr479b.html>
  */
 static long const pulsewidth = 250000000; /* nanoseconds */
 
@@ -14,8 +17,10 @@ static long const pulsewidth = 250000000; /* nanoseconds */
  * stopping it, in seconds.  The point where it's faster to stop the
  * clock than to advance it is around 11:35 forwards (0:25 backwards),
  * but this is set a little lower so that setting the clock back for
- * the end of summer time is done by stopping, in accordance with
- * Synchronome's documentation.
+ * the end of summer time is done by stopping, in accordance with Post
+ * Office Engineering Instruction B 5301.
+ *
+ * <http://gpoclocksystems.byethost22.com/pages/b5301.html>
  */
 static int const maxadvance = (10 * 3600) + (50 * 60);