I am looking for a way for coders to easily reference the first instance of each code. Coding is frame by frame, and I am picturing the first time a coder labels a frame "a", the frame being pinned to the screen with the label "a" so that each time "a" comes up again, the coder can reference the pinned frame to know what "a" looks like...and so on for b,c,d. Is this possible in datavyu? Thanks so much!