object/letter/3 matches the site

public static HumanMadeObject Letter_In_Box()
{
    var obermeyer = new HumanMadeObject()
        .WithContext()
        .WithId("https://linked.art/example/object/letter/3")
        .WithLabel("Obermeyer 1920");

    obermeyer.IdentifiedBy = [new Name("Obermeyer, Bertha (1920)").AsPrimaryName()];

    obermeyer.MemberOf = [
        new Set()
            .WithId("https://linked.art/example/set/archive_sfl")
            .WithLabel("Stieglitz Family Letters")
    ];

    obermeyer.HeldOrSupportedBy = [
        new HumanMadeObject()
            .WithId("https://linked.art/example/object/box55")
            .WithLabel("Archival Box 55")
    ];

    return obermeyer;

}

• Role shortcuts AsPrimaryName, AsAccessionNumber and AsSystemAssignedNumber each add a single classification, with the AAT terms Primary Name, Accession Number and System Number.

var humanMadeObject = new HumanMadeObject
{
    Context = ["https://linked.art/ns/v1/linked-art.json"],
    Id = "https://linked.art/example/object/letter/3",
    Label = "Obermeyer 1920",
    IdentifiedBy =
    [
        new Name("Obermeyer, Bertha (1920)")
        {
            ClassifiedAs = [Aat.PrimaryName],
        },
    ],
    MemberOf =
    [
        new Set
        {
            Id = "https://linked.art/example/set/archive_sfl",
            Label = "Stieglitz Family Letters",
        },
    ],
    HeldOrSupportedBy =
    [
        new HumanMadeObject
        {
            Id = "https://linked.art/example/object/box55",
            Label = "Archival Box 55",
        },
    ],
};

Generated from the object the example builds: every property that is set, as object initialisers, with the vocabulary constants where a term is in the registry. The fluent helpers are a convenience, not a requirement; this form and the one as written produce the same JSON.