Problem: Want to HIDE a Custom Field that is no longer needed on PDF transactions... Books won't let me

Problem: Want to HIDE a Custom Field that is no longer needed on PDF transactions... Books won't let me




So I have a custom ITEM field which we displayed on templates. We no longer want to show the custom field on templates but have it available HOWEVER when I try to change it to "Do not show on PDF transactions" it says

Almost there, but...
  • Transactions have been created with the custom field. Hence it cannot be deleted.

I am not deleting the custom field... I just want to NOT SHOW on PDF Transactions. 

Another issue... how am I supposed to know what transactions have the custom fields if it does not tell me.