Prohibition of selling dogs to people without a BREEDING license

When the user posts an ad and selects "YES" in the "DOG BREEDING LICENSE HOLDER" condition, then and only then should the transaction type display the "SELL" option. How is this done?

That sounds like very specific requirement for dogs selling. Easiest way will be custom code.

Can the product brand and model in the plugin (Products Attributes Plugin) be hidden based on a contition selection—such as "used"—by wrapping them in a function like this?
<?php if(!osc_is_web_user_logged_in())  { ?>
----------
<?php } ?>

I am wrapping `Item.edit.php` from `products_attributes` with this code, but it doesn't hide the brand and model when the condition is 'Used'.
<?php  if ($item_condition = 'Used') { ?>
------
<?php } ?>