Can the numero sign (№) only be used to indicate ordinal numbers only, or would it be correct to use it for cardinal numbers as well?

A very specific example: if I write about "the number of males observed in the sample", could I use "№ of males in sample" for a table header? Or is that usage strictly speaking correct only for usages such as "observation № 22"?

  • I have seen this discussion, but the answer given there is not completely clear to me…So I'll take the risk of being marked duplicate and revive the discussion.
    – Matthijs
    Commented Mar 9, 2015 at 14:36
  • Even if you can, why would you want to? For your example, why not just use "males in sample" or just "males" if you want to shorten it? Commented Mar 9, 2015 at 14:59
  • True, it is a slightly concocted example…but it could be that there is also individual information, and "males in sample" could have individual names, followed by columns of age, sex, …. You would then need a "№" or "Number of" column to distinguish. In any case, I see similar constructions sometimes, and always wonder if the usage is correct (even if not stylistically appropriate).
    – Matthijs
    Commented Mar 9, 2015 at 15:09
  • 2
    May be I'm wrong, but isn't the hash the American English version of the Numero sign? If so, the same question applies.
    – Matthijs
    Commented Mar 9, 2015 at 15:14
  • 1
    In the UK at least, I've seen plenty of uses of the similar "No." (e.g. "No. of males in sample") which do not result in confusion. Although you should probably avoid it in formal writing and limit its use, as you say, to table headings where it's strictly necessary to save space. You might find this lengthy discussion interesting. Commented Mar 9, 2015 at 15:27

1 Answer 1


I don't think there is a universally accepted formal answer to this. This answer is my own style, which is reflected by Wikipedia.

From Wikipedia's article on the numero sign,

№ is a typographic abbreviation for the word number(s) indicating an ordinal numeration, especially in names and titles.

Use № only when you are using numerals (not when the number is spelled out), and only when you are referring to the number as an identifier/designation rather than as a quantity.

So I would advocate for:

  • Observation № 22
  • Now serving № 8
  • Insert part № 3 into slot 7

I would advocate against:

  • № of males in sample 5
  • Now serving № eight
  • Wow, that was home run № 3!

You also brought up using numero signs in tables. It is considered acceptable to bend style guidelines when it comes to layout and other graphic design; if "№" fits where "number" does not, feel free to use the shorter version.

(There is also an archaic usage for the numero, in which it may be used to indicate quantity, as "№" does have a definition in which it means "in number," but I've never seen this usage in practice.)

  • 1
    Thanks, would vote up but cannot…Wikipedia says No is an "abbreviation of the word number(s) indicating ordinal numeration" (my emph), which is why "№ of males in sample 5" feels awkward to me, but "Number of males in sample № 5" does not. I agree that lay-out and design allow some leeway.
    – Matthijs
    Commented Mar 10, 2015 at 9:58
  • @Matthijs you are correct. I must have read the wikipedia article too hastily; wikipedia actually agrees with my style. I have updated my answer to note that. Thanks!
    – Adam Katz
    Commented Mar 10, 2015 at 16:07

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