I've asked this question to support but got a non related answer:

I have a RLC-520, and I download a new firmware it says:

"Firmware for hardware version IPC_515B16M5M
If your model is not listed above or the hardware version of your camera is not the
exact number listed above, please do not upgrade this firmware. If you upgrade wrong
firmware,it may brick your camera."

My camera says IPC_51516M5M without the 'B' in the middle. Can I use this firmware without bricking my camera?

-M