Extended Addressing (10-bit)
Due to the increasing popularity of the I2C bus the 7-bit address space got exhausted. This started posing problems for people currently in the phase of designing a new I2C compatible IC. Therefore the I2C standard has been updated to implement a 10-bit addressing mode.
A chip that conforms to the new standard receives two address bytes. The first consists of the extended addressing reserved address including the 2 MSB's of the device address and the Read/Write bit. The second byte contains the 8 LSB's of the address.
This scheme insures that the 10 bit addressing mode stays completely transparent for the other devices on the bus. Any new design should implement this new addressing scheme.