The Lancet, one of the top medical journals in the world, requires 'Type decimal points midline (ie, 23·4, not 23.4)'. Does anyone know why this is? As a mathematician, I'll always read 23·4 as 92. Seems odd to me that such a high profile paper would insist on such a strange formatting choice, which goes against the SI standard, so I'm guessing there's a good reason for it.
This notation was more common historically, particularly in the British empire. My guess would be that the Lancet, being an old journal founded in England in 1823, is sticking with it because of tradition rather than a really good reason.
To expand on @Anyon's answer more generally, mathematical notation is not universal between countries. Where the decimal symbol appears—and what the decimal symbol even is—varies significantly. For instance, in most of continental Europe, the period and comma are switched so that what in the US would be "24,321.12" would be "24.321,12" in Germany or the Netherlands. Similarly, the "dot product" is sometimes written on the baseline rather than on the center line.
So this is just an expression of a stylistic preference or tradition.
The unspaced centred dot, as in 23·4 (= 234 ÷ 10), means the decimal point. To denote multiplication, spacing is necessary: 23 · 4 = 92. As long as one sticks to this convention, no confusion arises. From some people's point of view, it is nice to distinguish thus the marker for decimal point from those for multiplication and the end of a sentence.