A lighting unit includes a power supply, a light source, a controller, and an output intensity adjustment mechanism. The adjustment mechanism is configured to allow a user to set an output intensity of a plurality of non-zero intensities generatable by the light source. The controller is operable to control a supply of electrical power from the power supply to the light source such that the light source illuminates in accordance with the intensity set by the user. The lighting unit is also operable to optionally report usage information for the lighting unit (e.g., cumulative on time) using the light source to produce a visually undetectable information signal. The controller is further optionally operable to adjust (e.g., increase) the electrical power supplied to the light source when the cumulative on time for the light source corresponds to a point on a lumen depreciation curve indicating a reduction in light source intensity.