A value document has a security marking in the form of at least two luminescing substances which are present in a defined relative quantitative share and are jointly excitable by one excitation pulse. The time courses of the intensities are different and at least one luminescing substance has a non-monoexponential time course. In a method for identifying the security marking, the time course of the total intensity is detected and a linear combination of a formula is adapted including time courses of the intensities of the luminescing substances. The security marking is identified on the basis of the linear coefficients.