Back when the game first launched instead of using shards for crafting there were these unique drops, with each recipe requiring a specific item. When they switched over to shards, they couldn't remove the old recipes from people's crafting panels who had already read a recipe, so they let the old items continue to drop so that people who still had one of those old recipes would still be able to make them.
By now there are basically none of the old recipes left, so these drops are just vendor trash.
Mirkwood changed all of the legacy recipes to require shards. I had 8 or so (old) recipes learned, now I just have duplicate one shots that require shards.