Dan,
From the 03 IRC:
R 311.5 Stairways.
311.5.2 Headroom.
The minimum headroom in all parts of the stairway shall not be less than 6 feet 8 inches (2036 mm) measured vertically from the sloped plane adjoining the tread nosing or from the floor surface of the landing or platform.
311.5.7 Illumination.
All stairs shall be provided with illumination in accordance with Section R303.6.
303.6 Stairway illumination.
All interior and exterior stairways shall be provided with a means to illuminate the stairs, including the landings and treads. Interior stairways shall be provided with an artificial light source located in the immediate vicinity of each landing of the stairway. For interior stairs the artificial light sources shall be capable of illuminating treads and landings to levels not less than 1 foot-candles (11 lux) measured at the center of treads and landings. Exterior stairways shall be provided with an artificial light source located in the immediate vicinity of the top landing of the stairway. Exterior stairways providing access to a basement from the outside grade level shall be provided with an artificial light source located in the immediate vicinity of the bottom landing of the stairway.
I would not comment on it as long as it did not intrude on the 6'8" headroom space.
Folks carrying large objects just need to watch there surrounding
