pmpro_checkout_signon_secure

Force PMPro to login over http or https in case other plugins (like WordPress MU Domain Mapping) conflict with what should be chosen here

pmpro_required_billing_fields

Filters the required fields for the Billing Address section on the checkout page. Passes the array of field names.

pmpro_registration_checks

Executes custom code which runs after the order has passed validation, before the registration is continued. Can be used to add custom validation.

pmpro_checkout_oldemail

This hook controls whether or not to allow registrations with email addresses which have already been used. By default, PMPro does not allow multiple registrations with one email address and shows an error if the email address has already been used.

pmpro_wp_new_user_notification

Controls whether to send the default WordPress new user notifications when a user is created at checkout. By default, this is set to false.

pmpro_checkout_start_date

This hook pmpro_checkout_start_date allows you to change the start date of a membership before checkout.

pmpro_discount_code_level

This filter modifies the level  given by a discount code.  It passes the level object and the discount code ID.

pmpro_required_user_fields

Filters the required fields for the Account Information section on the checkout page. Passes the array of field names.