Constant NOT_AT_ROOT_CODE 

pub const NOT_AT_ROOT_CODE: &str = "not-at-root";

What: The finding code of a require-root rejection. &str is borrowed text baked into the program. Why: Callers and transcripts identify the finding by this stable code.

In TS you’d write (pseudocode):

export const NOT_AT_ROOT_CODE = 'not-at-root';