type FQDNOptions = {
    /**
     * Require presence of top level domain
     * @default true
     */
    requireTld: boolean;
    /**
     * Allow underscores in the domain name
     * @default false
     */
    allowUnderscores: boolean;
    /**
     * Allow trailing dot
     * @default false
     */
    allowTrailingDot: boolean;
    /**
     * Allow numeric top level domain
     * @default false
     */
    allowNumericTld: boolean;
    /**
     * Allow wildcard domain
     * @default false
     */
    allowWildcard: boolean;
    /**
     * Ignore max length for domain name
     * @default false
     */
    ignoreMaxLength: boolean;
};
export declare function isFQDN(str: string, userOptions: Partial<FQDNOptions>): boolean;
export {};