Where and How to make the change on R12 (just as it was changed in “adovars.env” of 11i)

Hi Experts

Could you please share me advice on this?

When a customer used EBS 11i, he added something manually to adovars.env.

Now the upgraded EBS to 12.1.3, they want to know "On which file and How to do the same thing on EBS 12.1.3?"

I did a research and find that

On 11i , changes were lost every time AutoConfig ran except the changes were written between the following words:

  -------------------------

   # Begin customizations

   # End customizations

  -------------------------

But on 12.1 I did NOT find the words "# Begin/End customizations" in $APPL_TOP/admin/adovars.env , should they add this words by themselves and then add their customization