When Sony unveiled its new Xperia Z4 smartphone in Japan this week, the company made no mention of extra-big or extra-small models. But it looks like there may be Sony Xperia Z4 Ultra and Compact editions on the way.
Documents related to a few unannounced Sony phones showed up at Indonesian regulatory site Postel recently, and according to the folks at Sogi, the model numbers suggest these could be Xperia Z4 Ultra and Compact phones.

Sony has released “Compact” versions of 2Â out of 3Â Z-series smartphone since the Xperia Z1. These are usually phones with smaller and lower-resolution displays and smaller batteries, but which have many of the same hardware features as their larger counterpart.
Meanwhile the “Ultra” line typically feature larger screens.
We don’t know much about the expanded Xperia Z4 family yet, but the first Sony Xperia Z4 smartphone features a 5.2 inch, full HD display, 3GB of RAM, a Qualcomm Snapdragon 810 processor, and a 2930 mAh battery. It has a 20.7MP rear camera and 5.1MP front camera.
The new phone has a newer processor than the Xperia Z3, but less battery capacity. It will be available exclusively in Japan at launch, but it’s possible that Sony has an international version in the works. Perhaps it’ll be announced at the same time as the Xperia Z4 Ultra and Compact.
via GSM Arena
There was a rumor at one point that it was just going to be a smaller device and the Ultra. Maybe for the rest of the world besides Japan that will be the case. But, I don’t trust Sony anymore. They are a ticking time bomb on whether they’ll just drop their mobile division entirely.
The idea of a quad HD Ultra in the 6 inch range with Xperia design language does interest me a little bit, but not as much as before.
There was no Z2 compact , only Z1 and Z3.
Whoops. My Google-fu failed me when looking that up.