Grade is a required question in the registration form and cannot be removed.

To change the grade as of year in the registration form:
  1. From the Home screen, Click Setup below the Season Name
  2. Click Sessions 
  3. Select any session that has a grade restriction
  4. Scroll down to Grade Restriction and Click Edit
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       5. Click the Dropdown Arrow to select the Grade as of Year

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Note : This will update the information on the registration form.  You only have to make the change in one session, this will update all other sessions and the registration form question for that season.