Unless it complins, I'd expect you could get away with a 200mA device on one port, if the other ports add up to less than 200.
It stems from the device power grading.
A standard high power device, which can ONLY be driven by a system port or powered ("self powered") hub, is 500mA.
A standard low power device, is 100mA.
So a 4 port, unpowered ("bus powered") hub, can drive 4 standard low power devices.
This is complicated by self powered devices (eg. Printer, camera docking station with PSU) which consume no power from the bus, or a nominal 2mA for presence detection. devices that lower than the 100mA, and devices that are higher.
Golden rule, if what you connect to an unpowered hub, plus the small demand of the hub itself, exceeds 500mA, then you WILL have problems - if the system is doing it's job, it will force an overcurrent shutdown of the hub or the devices on it.
If you can find the hub in device manager (generic hub, not "root"), then the "power" tab will tell you the current device power indications - they are power "requests", not measurements, as each device declares a maximum requirement, and then the USB subsystem should allow or deny it accordingly.
PS. My external bus powered hub is detected as self powered, and classified as 500mA per port, completely wrong!