Contrast curves are used to assess the flux ratio which can be achieved between a planet and a star in a particular observation and instrument. This is dependent on the separation from the star, and thus a curve is generated, rather than a single contrast value across an image.
These contrast curves are maintained by V. Bailey at here and have been generated using the B. Nemati spreadsheet.
Each file contains the contrast curve for each mode and has information in the header which explains the instrument set-up, assumptions, integration times, and stellar magnitudes.