R12 : How to run adpatch in order to checl the pre-requisite options=checkprereq ??

Hi,

We are planning to install the VCP 12.1.3.8 PATCH (14247039) and in their readme.txt says:
Please apply adpatch with the options  = checkprereq to ensure that all
necessary prerequisites have been applied successfully before applying this
patch..
We trying the following options:
adpatch options=prereq
option: "prereq" is not supported on R12
and
adpatch options=checkprereq

Ignoring unrecognized option: "checkprereq".


PATCH README
===============

General Instructions for applying this patch
============================================

Please apply adpatch with the options  = checkprereq to ensure that all
necessary prerequisites have been applied successfully before applying this
patch.

Please bring down the application server before applying this patch.

Please make sure that there are no active sessions before starting to apply