Why do you say "a little steep?" Clearly if you understand what is going on
there would not be a question. (assuming US/FAA)

vfr traffic 500 feet above/below
altimeter error allowed - 75 feet.
deviation of 100 feet
deviation of VFR traffic - 100 ft

Add up those errors and you have only 150 ft of separation



"Magnus" wrote in message
...
I thought it was +/- 200 feet before you've violated if you are flying
IFR, but someone just told me it's a 100 feet, which seems a little
steep considering they use 1000 feet separations.