This set was produced to introduce a more comprehensive set for these classes, which hadn't been done by previous manufacturers.
Locomotive Pilot Assignments helped designate which engine house a locomotive was assigned to for its annual refit and repairs. All Pennsylvania Railroad locomotives are to have had their regular assignments stenciled onto the right-side front of their pilot, see diagram for proper placement.
Enough data is included for 4 locomotives using one specific Region assignment. Data was inconclusive about whether assignment symbols were abbreviated with a period between each letter or not, so both variations were included in this decal set where applicable.
The pilot lettering for Steam Locomotives is 3” Tall, pilot lettering for Diesel Locomotives & Electric Motors it is 1 ¾” Tall. Please consult numerous commercial publications for examples.