Thanks to David for this odd sign:
MRP isn’t exactly sure what exit discharge is. The words are related in a way but not synonymous, so it’s not exactly redundant. There are a million meanings for discharge, but this is probably the closest relevant one where it’s used as a noun (according to American Heritage):
3 a. A flowing out or pouring forth; emission; secretion: a discharge of pus. c. Something that is discharged, released, emitted, or excreted: a watery discharge.
Possibly, the author of this sign had other, less unsavory meanings of the word, commonly used as a verb, including:
To let go; empty out: a train discharging commuters. To pour forth; emit: a vent discharging steam.
Either way, um, ew. You might want some Purell for that.