Embodiments include an article of manufacture, apparatus, device, system, computer-program product, and method. In an embodiment, system is provided that includes at least two machine-differentiatable identifiers, each identifier of the at least two machine-differentiatable identifiers being respectively keyed to a data recipient and associatable with a hand-formed mark on a surface. The system also includes a commonly accepted meaning respectively associated by a group of users with each machine-differentiatable identifier of the at least two machine-differentiatable identifiers. The system may include a surface displaying the at least two machine-differentiatable identifiers. The system may include a surface displaying the at least two machine-differentiatable identifiers and the commonly accepted meaning respectively associated by a group of users with each machine-differentiatable identifier of the at least two machine-differentiatable identifiers.