Project
This field is required on a financial document detail line item if the Account entered on that line item has been identified as a project related account (that is, if the Account was configured on the Admin >> Setup >> Accounts screen with the Require Project indicator checked). Otherwise, it is not allowed.
Note: There is an exception to that rule: if the item is marked as an inventory item, then it cannot have a project, or be associated with an account that requires a project.
The projects available will be limited to:
Those that have an Owning Organization that belongs to the same Legal Entity as the Legal Entity defined on the Financial Document
Those that are associated with a Project Status having the Active indicator enabled