README.rdoc in fluent-plugin-datacounter-0.4.0 vs README.rdoc in fluent-plugin-datacounter-0.4.1

@@ -83,11 +83,11 @@
       count_key status
       pattern1 OK ^2\d\d$
       pattern2 NG ^\d\d\d$
       input_tag_remove_prefix accesslog
       output_per_tag yes
-      add_prefix status
+      tag_prefix status
     </match>
     # => tag: 'status.foo' or 'status.bar'
     #    message: {'OK_count' => 60, 'OK_rate' => 1.0, 'OK_percentage' => 70, 'NG_count' => , ....}
 
 And you can get tested messages count with 'output_messages' option:
@@ -108,10 +108,10 @@
       count_key status
       pattern1 OK ^2\d\d$
       pattern2 NG ^\d\d\d$
       input_tag_remove_prefix accesslog
       output_per_tag yes
-      add_prefix datacount
+      tag_prefix datacount
       output_messages yes
     </match>
     # => tag: 'datacount.baz'
     #    message: {'messages' => xxx, 'OK_count' => ...}