woods@most.weird.com (Greg A. Woods) writes:

> Yes, I believe upper case abbreviations are preferred (or perhaps even
> required) by SI for metric measurements.

    III.1 SI prefixes
    
    The 11th CGPM (1960, Resolution 12) adopted a first series of
    prefixes and symbols of prefixes to form the names and symbols of
    the decimal multiples and submultiples of SI units. Prefixes for
    10 15 and 10 18 were added by the 12th CGPM (1964, Resolution 8),
    those for 1015 and 1018 by the 15th CGPM (1975, Resolution 10),
    and those for 1021, 1024, 10 21, and 10 24 were proposed by the
    CIPM (1990) for approval by the 19th CGPM (1991).
    
    TABLE 7

    SI prefixes

    Factor	Prefix	Symbol
    10^24	yotta	Y
    10^21	zetta	Z
    10^18	exa	E
    10^15	peta	P
    10^12	tera	T
    10^9	giga	G
    10^6	mega	M
    10^3	kilo	k
    10^2	hecto	h
    10^1	deka	da
    10^-1       deci    d
    10^-2	centi	c
    10^-3	milli	m
    10^-6	micro   (my)
    10^-9	nano	n
    10^-12	pico	p
    10^-15	femto	f
    10^-18	atto	a
    10^-21	zepto	z
    10^-24	yocto	y

/Johan