When using the note-card system, what goes in the upper right-hand corner of the card?

The upper right-hand corner of the note-card contains the source information.

Typically it contains the name of the author and / or the page number where the information on the card was found. Sometimes if you're also using source cards, the upper right-hand corner will contain a source number so that you can reference your source card for the necessary information. The top of the note-card should be titled with the topic the information will address or support.