In some contexts, FU codes are used for fuel types or specific logistical routes, which might relate to the "crawling" (slow movement) of transport through the mist-heavy Galician mountains at night.

On clear nights, some say she sleeps beneath the jetty in a hollow of sea-wet stone. Others swear they saw her standing in a doorway, looking at a child who never learned to swim. The child paddled along the shallows and came home smiling, pockets heavier with seashells. In the morning the child could not remember the visit, except for a song hummed under the breath—a tune that tasted of iodine and peppermints.