L is better than l because it is less ambiguous.
> From: Bill Hooper <[email protected]> > Reply-To: <[email protected]> > Date: Tue, 22 Sep 2009 15:03:02 -0400 > To: "U.S. Metric Association" <[email protected]> > Subject: [USMA:45876] Re: History of Units > > > > On Sep 22 , at 12:44 PM, Teran McKinney wrote: > >> >> Metric is so beautiful in comparision: >> 200ml -> 0.2l >> 200l -> 0.2kl >> >> 200mg -> 0.2g >> 200g -> 0.2kg > > It's even more beautiful if you follow the rule that there should > always be a space between the number and the unit. Your list should > read: > 200 ml -> 0.2 l > 200 l -> 0.2 kl > > 200 mg -> 0.2 g > 200 g -> 0.2 kg > > The value of such a practice is very clearly seen in the value of two > tenths of a litre; you have written it as "0.2l" which can easily be > misread as "twenty-one hundredths" because the el (l) looks an awful > lot like a one (1). In some fonts they are identical. Writing it as > "0.2 l" makes it clear (or at least a little clearer) the the "l" is > an el for litre not a one. > > Similarly, your 200l looks suspiciously like "two thousand one". > Writing "200 l" instead helps to make it clear that it represents 200 > of something and the "l" will then be interpreted as the litre symbol. > > (One can also use the capital "L" for litre to reduce the ambiguity > further. Currently both "l" and "L" are correct but CGPM promotes the > idea that eventually one or the other should be universally adopted > and the other deprecated.) > > In an admitted minor point, I wonder why you used the cute little > arrow ( -> ) instead of just using an equals sign. > > I interpreted the arrow this way (for example): > "200 mg -> 0.2 g" means "200 mg converts to 0.2 mg". That leaves me > with the subtle concern that maybe the reverse is NOT true! Of course, > it should be understood to mean that the conversion works either way. > But, since it works both ways, then shouldn't the arrow point both > ways; wouldn't it then be more appropriate to write it as "200 mg <--> > 0.2 g"? > > Then again, why not just use an equals sign which is readily > interpreted to mean the two are EQUAL so that it can be used to > convert either way. >
