While a documentary credit is used to effect payment for goods and services, a bond/guarantee/indemnity or standby letter of credit serves as a binding commitment given by CMB that an applicant will fulfill his obligations under a commercial contract.
CMB can issue such an instrument for you to support a number of situations including bid or performance under a contract, advance payment and payment to a supplier.
In addition, CMB can also provide standby letter of credit for the similar purposes.