## Typesetting Mathematics According to the ISO Standard [Access to ISO 80000-2:2009]

Typesetting Mathematics According to the ISO Standard by Nick Higham.

From the post:

In The Princeton Companion to Applied Mathematics we used the conventions that the constants e (the base of the natural logarithm) and i (the imaginary unit), and the d in derivatives and integrals, are typeset in an upright font. These conventions are part of an ISO standard, ISO 80000-2:2009. The standard is little-known, though there is an excellent article about it in TUGboat by Claudio Beccari, and Kopka and Daly’s A Guide to $\LaTeX$ has a page on the standard (in section 7.4.10 of the fourth edition and section 5.4.10 of the third edition).

Nick mentions that you can get a copy of ISO 80000-2:2009 for about \$150, and he also says: