We have made a proposal for a standard input format for the specification of (large-scale) nonlinear programming problems. In its full generality, the user needs to provide three input files. The first describes the structure of the problem and the decomposition of the problem into group and element functions. The second and third then specify the values and derivatives of these functions. It is anticipated that the first file will be used to provide input parameters for a user's optimization procedure, while the remaining two will be used to generate problem evaluation subprograms.