I tried to find whether this has already been discussed but I could not find anything. I am using beta 021. In the tutorial there is a passage that says:
"Alternatively, if a Corner Mark is selected in the Options the corner of each index card will be the color of the label associated with it. You can also select Show Stamps via View > cork board, which places a diagonal stamp on the cards—this stamp shows the status associated with the document represented by the index card"
Neither of these seems to happen. Using the options to choose pin instead of lable works but not the other way around.
Worked it out. Apologies.