If you wrote the check, the only way to guarantee that you will not be liable for it longer than six months is to place a stop payment order on it. According to Bankrate.com, an oral stop-payment order expires after 14 days and a written stop-payment order expires in six months.
Mb-a unit of information equal to 1000 kilobits or 10^6 (1,000,000) bits. Mbit, megabit. computer memory unit-a unit for measuring computer memory. kb, kbit, kilobit-a unit of information equal to 1000 bits. Gbit, gigabit, Gb-a unit of information equal to 1000 megabits or 10^9 (1,000,000,000) bits.
Orders of magnitude of data. The megabyte is a multiple of the unit byte for digital information. Its recommended unit symbol is MB, but sometimes MByte is used. The unit prefix mega is a multiplier of 1000000 (106) in the International System of Units (SI). Therefore, one megabyte is one million bytes of information. This definition has been incorporated into the International System of Quantities. However, in the computer and information technology fields, several other definitions are used that arose for historical reasons of convenience.