Torrc's bandwidth entries are more flexible than documented
According to the tor man page the permitted format for bandwidth entries is pretty simple...
RelayBandwidthRate N bytes|KB|MB|GB
Arm parses these to check if the torrc is out of sync with tor's actual state (ie, that the user edited their configuration without restarting or issuing a sighup). However, a user inadvertently found that tor is actually more flexible on these lines that what the man page documents...
12:54 < atagar> What is the exact torrc lines that you have?
12:55 < Urban_core> RelayBandwidthRate 250Kbytes # Throttle traffic to 100KB/s (800Kbps)
12:55 < Urban_core> RelayBandwidthBurst 350Kbytes # But allow bursts up to 200KB/s (1600Kbps)
Once this is fixed in the tor man page please assign this to the arm component and I'll fix it on my end.