Machinable
Magento\Usps\Model\Source\Machinable
What it does
This class provides USPS machinable parcel options for shipping configuration in Magento 2.
Developers use this source model to populate dropdown options in the admin panel for configuring whether a package meets USPS machinable requirements, which affects shipping rates and service eligibility.
It extends the Generic source class to load predefined machinable options from the USPS carrier configuration.