Fun fact -- did you know that this requirement is only because UA doesn't want to deal with the seatbelt requirements being different? According to regulations there is not requirement for any straight forward facing seat to have a shoulder strap -- only the angled ones -- but the drama created by different requirements for seatbelts in J would just be too much for the crews -- therefore EVERYONE must wear a shoulder strap -- even though for half of the cabin it's not required.... The shoulder strap requirement is only due to the angle of the seats -- nothing more....