diff --git a/croppa/spec.md b/croppa/spec.md
index 58d9135..bcb0d02 100644
--- a/croppa/spec.md
+++ b/croppa/spec.md
@@ -20,6 +20,12 @@ Likewise when accepting user input from the processed display frame the coordina
 A simple example if we are rotated by 90 degrees and click on the top left corner of the display frame
 That coordinate is to be mapped to the bottom left corner of the original raw unprocessed frame
 
+The input to the editor is either a list of video files
+Or a directory
+In the case a directory is provided the editor is to open "all" editable files in the given directory
+In the case multiple files are open we are able to navigate between them using n and N keys for next and previous file
+Be careful to save and load settings when navigating this way
+
 ## Core Features
 
 ### Video Playback