So I met a lady in the pub the other night, thought I'd see if I could entice her to come home with me. Said I'd cook her breakfast in the morning and asked "how do you like your eggs?"
"Unfertilised", was the answer with a rather withering look.
Spanish onion: has a similarly coloured skin to a yellow/brown onion, but is usually bigger, as well as sweeter and milder - good for omelettes, salsas and stir-fries.
So it's probably a "marketing thing". Over here they are sold as Spanish Onions.
Salad onion?, spring onion is the marketing term here.