How Does Step Up PEP Define Income?

Step Up's document 1070NP - Non Income Priority displays "Annual Maximum Gross Income Cap".

Does anyone know how they define this? For example, is this is IRS Form 1040, line 11 (adjusted gross income) or Line 15 (taxable income) which is usually significantly less.

For reference: Page 10 of PEP Parent Handbook (linked here):

Proof of Income

To be considered for application priority, the scholarship application must list all income sources for all household members 18 years or older. Sources of income include:

• Paychecks

• Cash wages

• Self-employment or business income

• Unemployment benefits

• Social Security

• Income/disability for every household member (including children)

• Child support

• Interest or investment income