Job Cards or Job Control Cards were cards which acted as a header for a single run of a set of cards for a particular user. As bundles of cards were often input into a computer by computer operators, rather than the card’s author, they provided a method of identifying a job, and the author. When compared to other cards in use, they were often a contrasting color, or had a contrasting colour band. This allowed these cards to be found easily, allowing operators to stack multiple jobs together in a single stack of cards, and easily identify where each job started, and the last job stopped.

Job cards could be punched with simple sets of information like the name of a job, parameters for running the job, or limits (such as memory or time limits) to be applied to identify to the job when it was run. In large institutions this information also often also included the user, a faculty or department, and who the costs of the computing time could be billed to.