In Agile Designer, all flows end with a .VTF extension.
What does VTF stand for?
CA Agile Requirements Designer (ARD), formerly Test Case Optimizer (TCO)
All product release versions.
VTF stands for Visual Test Flow. When Agile Designer was first developed by Grid Tools, the product name was called Visual Test Flow. The developers kept the file extension .VTF even after the product name changed to Agile Designer. This file type is the only compatible file for opening flows in Agile Designer, although you will be able to import other file types. When you save a flow, it is automatically saved as the .VTF file type.