The existence of a dilepton subsection in the collision term section of the configuration file enables the dilepton production. In addition, the dilepton output also needs to be enabled in the output section and dilepton decays have to be uncommented in the used decaymodes.txt file. The output file named Dileptons (followed by the appropriate suffix) is generated when SMASH is executed. It's format is identical to the collision output (see OSCAR collisions format), it does however only contain information about the dilepton decays.
Further, the block headers differ from the usual collision output:

# interaction in nin out nout rho density weight shining_weight partial part_weight type proc_type

where

nin: Number of ingoing particles (initial state particles)
nout: Number of outgoing particles (finalstate particles)
density: Density at the interaction point
shining_weight: Shining weight of the interaction. Explanation follows below.
part_weight: The partial weight of the interaction. For the dileptons, this coincides with the branching ratio.
proc_type: The type of the underlying process. See process_type for possible types.

Note, that "interaction", "in", "out", "rho", "weight", "partial" and "type" are no variables, but words that are printed.
The dilepton output is available in binary, OSCAR1999, OSCAR2013 and OSCAR2013 extended format.

Note: As dileptons are treated perturbatively, the produced dileptons are only written to the dilepton output, but neither to the usual collision output, nor to the particle lists.