Stock Items to have a minimum and multiples of order quantity for Sales Order Processing Merged

To enable a user to only enter a fixed figures on a Sales Order if there are manufacturing quantity constraints. i.e. If a product can only be made in cost effective batches of 200000, any attempt to save a sales order line with a non-conforming quantity e.g 180,000 or 225,000 would result in an error message, prompting the user to alert the customer to this fact and reassess how much they wish to order.