First off Steve, welcome to the board. If you are or become a keen 'glassie' you will find it to be a wonderful resource.
That is not a signature it is a fault in the mold where probably a small amount of air has been trapped. I suspect your vase comes from one of the very low production cost makers - Poland, Romania, China, etc. The design is very Scandinavian - Similar to many SEA glass items.
Ross