Serde + custom derive, is it possible to reuse constant?

Is it possible to use share constant with custom derive?

#[derive(Serialize, Deserialize)]
#[serde(tag = "type", rename = "xyz", rename_all = "camelCase")]
struct S {
   //some fields
}

I mean give name to "xyz" as share it withing my code base?

I tried:

macro_rules! foo {
    () => {
        "BOO"
    };
}

#[derive(Serialize, Deserialize)]
#[serde(tag = "type", rename = foo!(), rename_all = "camelCase")]
struct S {
    i: i32,
}

but compilation failed,
any way to share constant with custom derive? Or may be it is possible to get this constant from serde? Like <S as SerdeGetTagTrait>::tag() ?