Methods and structure for transferring administrative information through a communication interface. Features and aspects hereof provide for exchanging administrative information between an initiator device and a target device using read and write commands encoded with a reserved sub-tag value. In the context of a Serial Advanced Technology Attachment (SATA) system, a portion of a parameter (e.g., the LBA parameter) of a read or write command (a Native Command Queuing command) is defined to encode a sub-tag value. One or more sub-tag values are reserved to indicate that the corresponding read or write command is related to the exchange of administrative information rather than the reading or writing of data on a storage device. A parameter value encoded in the LBA field or data length field of the read or write command indicates administrative data to be returned to the initiator or to be updated within the target device.