I'm too stupid to know if it's a swan or a goose so here's a goose version instead if one of the 409 goose experts can assist.
One of the areas at my work is labeled E621 as part of the identification scheme they use where I work
The giggles from this that know is always a treat especially considering the person manning that station has no idea why some people giggle about it and in general is a stick in the mud.