Originally Posted by
zombietooth
Skypesos are Delta Airlines miles. They were given the denigrating name many years ago when DL devalued them massively and started dynamic awards.
Y-award in this instance is a RT economy class ticket. Some people book two one-way award tickets because there is little downside, and you have more flexibility.
Note that Delta awards to/from US/Canada have different award levels for roundtrip vs. one-way bookings on most long haul international routes. Buying as two one-ways will generally cost more miles than a roundtrip booking if there is inventory in the cheaper award level buckets. For awards that neither originate, nor end, in US/Canada, Skymiles awards generally all still seem to be bookable as one-ways at lowest levels.