In v3, after Account -> Convention Cards: You have a "New ACBL CC" button, a list of stock CCs, and a list of personal CCs. Each personal CC has a partner assigned to it. You can create a new CC, or clck on any CC to edit it, and change your partner's name (and then save it) to effectively create a new CC, which can be viewed and edited by both you and your partner. The Flash version and the HTML5 version will load the CC automatically when either of you sit across the other. You may need to clear this CC when your partner is replaced by someone who has no CC defined with you. in the HTML5 version, should be an option in the hamburger button.