Relation the packing slip line back to sales line

Is there any the relation from the packing slip line back to sales line ?

For example, we would like to know what sales line that this packing slip line come from.

Yes,

You can use InventTransId which will be unique for any inventory transaction.

Yes, each and every sales line will have a unique InventTransId. By using this InventTransId you can relate with its entire Sales transactions as well as Inventory transactions.

InventTransId, InventRefTransId and InventRefType are the useful fields for relation with Inventory transactions.

Thanks,

Vijay Solanki.