[1] The Laws of Duplicate Bridge specify that "Each partnership has a duty to make available its partnership understandings to opponents before commencing play against them.
"[2] In games regulated by the American Contract Bridge League (ACBL), this is generally done using a form with a standard format.
[3] The ACBL General Conditions of Contest specify that "Each member of a partnership must have a completely filled out convention card available for the opponents.
"[4] Convention card formats may vary by jurisdiction.
There are also various computer programs which a player may use to create and print a convention card.