In order to prevent clogging up your inquiries tab you can delete inquiries that you have fulfilled as well as inquiries that you do not intend to fulfill. You can do so by following the steps below
Open the catalogue whose inquiries you wish to delete.
Tap the Inquiries box on the top right of the Catalogue Screen.
Tap the Options menu on the top right hand corner of the Inquiries Screen.
Select the Select orders option in the Options Menu that pops up.
Select the inquiries that you wish to delete and then tap the delete button on the top right hand corner of the Inquiries screen.