Dressed for the Occasion is an achievement/trophy in the expansion A Criminal Past for Deus Ex: Mankind Divided. It is awarded for finding and putting on the yellow jumpsuit in the maintenance room in the area between the two cell blocks.
The jumpsuit is located in a locker in the maintenance room marked by the Secret Stash / Maintenance Mystery points of interest. The maintenance room is in area between the two cell blocks, and its location is marked in the map associated with the "Secret Stash" point of interest. Interact with the jumpsuit to complete the achievement.