Where do the eaves vent strips go when using underlay?

When using a non-breathable underlay in a cold roof, the underlay should be placed over the underlay support tray fitted above the eaves ventilation strip. When using a vapour-permeable underlay in either a warm roof or cold roof with an air impermeable roof covering, the underlay should be placed under the eaves ventilation strip in order to facilitate ventilation to the batten/counterbatten void beneath the roof covering.