By default, you can optionally include one or more card references in your log by typing a # in the description field. A menu will pop up showing all cards you are assigned to.
It might be desirable to require users to include a card reference in their logs, to enforce accountability on the task level. You can configure this per board in the board settings.
Card requirement settings.
Require a card reference for all logsWith this setting you force users to include a reference to a card in their logs. With this setting enabled but allow only one reference disabled, users must include at least one card reference: more than one is allowed.
Allow only one referenceThis setting makes Punchtime only accept logs that reference a single card. If you enable this setting but leave require a card reference for all logs disabled, cards references will not be required, but if they are included there cannot be more than one.