IBAN (International Bank Account Number): definition and validation

IBAN is unique identifier of a customer bank account within the international bank systems.

Validation techniques:
1) has length of no more than 34 symbols
2) includes only big letters (A-Z), and digits (0-9), no slashes, spaces, hyphens, etc.
3) first two characters are country ISO code  mo(DE for Germany, FR for France, etc.)
4) satisfies a special validation algorithm

IBAN validation algorithm:
1) First 4 characters of the IBAN are transferred to the end of the string
2) All characters are transaformed to numeric representation as follows: digits are converted to corresponding numbers ("3" -> 3), A to 10, B to 11, .. and Z to 35.
3) The created number is divided by mod 97. If the remained 1 is obtained from the division then the IBAN is valid.