%g a floating-point number, in %e or %f notation

The full piece of documentation is:

 %e    a floating-point number, in scientific notation
 %f    a floating-point number, in fixed decimal notation
 %g    a floating-point number, in %e or %f notation
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I think the last of those 3 is just shorthand for:

 %g    a floating-point number, in scientific notation or fixed decima
+l notation
[download]

Note that "%.*g" will give you scientific notation and "%*g" will give you fixed decimal notation (ie fixed to 6 digits of precision).
I think it's just meant to provide a quick indication of what "%g" formatting does, for anyone who is unfamiliar with it.
Those are the only excuses I can come up with ;-)

Cheers,
Rob