/**
 * Checks that tell a real identifier from a number that only looks like one. Every detector of card
 * numbers and account numbers uses them, so an order id or a millisecond timestamp is never masked as
 * a card.
 */
/** Whether a card number passes the Luhn check, with 13 to 19 digits; spaces and dashes are ignored. */
export declare function luhn(value: string): boolean;
/** Whether an IBAN passes its mod-97 check, with 15 to 34 characters; spaces are ignored. */
export declare function ibanChecksum(value: string): boolean;
/** Whether a phone-like match has as many digits as a phone number can: 10 to 15. */
export declare function phoneDigits(value: string): boolean;
/**
 * Whether a match reads as a phone number: 10 to 15 digits, written with a leading `+` or with
 * separators. A bare run of digits is an id or a timestamp far more often than a phone number.
 */
export declare function phoneNumber(value: string): boolean;
/**
 * Text as a detector should read it: Unicode compatibility forms folded (full-width letters become
 * ASCII), and the invisible characters an attacker uses to split a phrase removed, so
 * `ｉｇｎｏｒｅ` and `ig​nore` read as `ignore`.
 */
export declare function normalizeForDetection(text: string): string;