# Change fonts for units in siunitx

In the rules of typography for my language there is a rule, that units (only units, not numbers) should be displayed in different font than the rest of the text. E.g. if all of the text has serif font, units should be in sans serif font. It is pretty unclear from the manual if something like that could be achieved.

Also (this is perhaps breaking the rules, but it is waste of time and space post two so similar questions separately): siunitx displays `\SI{0.5}{\per\s}` as `0.5/s`. This is wrong, ISO 80000 requires displaying `0.5 s\$^{-1}\$`. I would like to have `{\m\per\s}` displayed as `m/s` and `{\per\s}` as `s\$^{-1}\$`. Is that possible?

Thanks for help.

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Just for information: what language is it? This rule seems quite peculiar. – egreg Sep 30 '13 at 21:39
Slovenian. I was told so by my proofreader. – Pygmalion Sep 30 '13 at 21:41
Did you see it in some book? Can you point to some source? – egreg Sep 30 '13 at 21:42
Maybe you ought to convey the information in the second paragraph directly to the package's author/maintainer (Joseph Wright) -- the more so as that paragraph seems wholly unconnected to the material introduced in the first. – Mico Sep 30 '13 at 21:46
Yes, proofreader showed me that rule in the book, that deals with formatting technical expressions. It is more like set of directions from language and technical experts. – Pygmalion Sep 30 '13 at 21:46