dj.1: debug output clarification

docs/dj.1

@@ -149,9 +149,10 @@ the following format:
 .R {ASCII record separator} {bytes written} {ASCII file separator}
 .RE
 
-If the
+This format for diagnostic output is designed to be machine-parseable for
+convenience. For a more human-readable format, the
 .B -H
-option is specified, the following format is used instead:
+option may be specified. In this event, the following format is used instead:
 
 .RS
 .R {records read} '+' {partial records read} '>' {records written}