--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/IMPL/Web/PreconditionException.pm	Fri Sep 04 19:40:23 2015 +0300
@@ -0,0 +1,33 @@
+package IMPL::Web::PreconditionException;
+use strict;
+
+use IMPL::declare {
+    base => {
+        'IMPL::Web::Exception' => '@_'
+    }
+};
+
+use IMPL::Resources::Strings {
+    message => "Precondition Failed"
+};
+
+sub status {
+    "412 Precondition Failed"
+}
+
+1;
+
+__END__
+
+=pod
+
+=head1 NAME
+
+C<IMPL::Web::PreconditionException> - The precondition given in one or more of
+the request-header fields evaluated to false when it was tested on the server.
+
+This response code allows the client to place preconditions on the current
+resource metainformation (header field data) and thus prevent the requested
+method from being applied to a resource other than the one intended.
+
+=cut
\ No newline at end of file