Definition of ironclad. 1  1 : sheathed in iron armor âused especially of naval vessels. 2  2 : so firm or secure as to be unbreakable: such asa : binding an ironclad oathb : having no obvious weakness an ironclad case against the defendant.
Best Answer: CR means a credit. If this appears on the balance due line of your statement, it means that you owe nothing and that you are that much ahead of future charges and no payment or acknowledgment is needed.
A cyclic redundancy check (CRC) is an error-detecting code commonly used in digital networks and storage devices to detect accidental changes to raw data. Blocks of data entering these systems get a short check value attached, based on the remainder of a polynomial division of their contents.