[atleastoptimal]

"legacy admissions" don't exist as an official thing, it's not like any school explicitly states how many legacy students it will admit. It's a term to address the phenomenon of those related to alumni being more frequently admitted

[detaro]

Places like Harvard do have explicit policies to give such students advantages, so no, it's very much an official thing.

[Symbiote]

They have "college attended" for each parent on the first page of the PDF application form.

Removing that would be easy.

[tnecniv]

It totally is an official thing or was when I applied. Statistics on legacy vs non-legacy admission rates and how legacy status was factored (the nature of the advantage you got varied by school) in were readily available when I was applying to schools.