From NSA advisory:
Certificates with named elliptic curves, manifested by explicit curve OID values, can be ruled benign. For example, the curve OID value for standard curve nistP384 is 126.96.36.199.34. Certificates with explicitly-defined parameters (e.g., prime, a, b, base, order, and cofactor) which fully-match those of a standard curve can similarly be ruled benign.
So basically the unexplained magic numbers in the published standard are totally secure.