How would you call out that in a BOM, or have it show in a drawing? Even in a shaded view, how could you balloon it or even point to it with a note?
The "decal" feature is just a way to get an image in a sketch to show in a shaded view. It might be poorly named.
Eventually I redid all my stickers with extrusions or embosses so they were clearer in shaded views and you could even read them in drawings (if the scale was right). I had a nice little folder in the library with the whole assortment. You kind of had to constrain to their origin planes, it's a little hard to constrain to an edge that is measured in mils. (Lining them up to each others' centers was better anyway when one is 3 1/4 wide and the next is 3 1/8 - I don't know if nobody talked to each other about how big they should be or maybe the problem was that one guy made them all and he was talking to himself.)
