||Yes, but there is no official documentation from Sony. I created my own Sony reference for the Z5 series.
Sony Z5 96k (not official)
from 11th February 2002 – 16 pages
compatible phones: Z18, Z28, (MZ5 ?)
standard AT commands of firmware version 3.8.4
compatible phones: J6, J16, J26, J7, J70, Z7
Old firmware versions need an extra space: AT<space>Command. All -S commands of the Z5 series are broken within these newer phones. A new command is introduced to access a upper level protocol: AT-SGBP=?