To have the gift say "Not Receipted" follow these steps:
  1. Access the donation or event form you do not want gifts to generated s "Receipted"
  2. In Tab 1 "Get Started" scroll to the very bottom where it says "Generate eReceipts"
  3. Uncheck the box
  4. Click Save and Close
This can not be done on a per gift basis, only a per form.