Which glyph(s) should be used to represent the word 'numero': N°, n°, or №?

Question

Which is the most correct/proper way to represent the word numero in metropolitan, standard written French? I have seen all 4 of the following in use:

№ (NUMERO SIGN U+2116)?

N° (an always capitalised 'N' followed by DEGREE SIGN U+00B0)?

n° (a lowercase 'n', except at the start of sentences, followed by DEGREE SIGN U+00B0)?

No. (the letters 'n' and 'o' followed by a full stop; I have seen both capitalised and non-capitalised permutations)

Answer 1

Using the degree sign is often done because it is directly available on a French (AZERTY) keyboard. That gives n° and N°. It looks like the famous perfume named N° 5 uses a degree sign:

             

Doing it is however sometimes considered incorrect because the degree sign is technically a small zero while the upper o is the vowel ending the word numéro. Using the degree sign also makes the plural unaesthetic to say the least: n°ˢ or n°^s.

To get a consistent display, you then need to use a superscript "o", possibly followed by a superscript "s" if plural:

Numéro: HTML: n^o or N^o, UTF-8: nᵒ or Nᵒ

Numéros: HTML: n^os or N^os and UTF-8: nᵒˢ or Nᵒˢ.

Sometimes, the masculine ordinal glyph is used as in nº and Nº. It is not recommended because depending on the font used, the o might be underlined which is not a French thing, and there is no matching "s".

Similarly, the "Numero glyph" (№) is unused in French because the "o" is underlined and there are neither lowercase nor plural forms.

Capitalization follows the generic rule, if numéro is starting a sentence, the initial N should be in uppercase, otherwise, a lowercase n is used.

Note also that a space is required after n^o, e.g.:

N^o 4

Answer 2

Selon le « Lexique des règles typographiques en usage à l'imprimerie nationale » qui fait référence, on trouve dans la liste des abréviations :

soit :

• n° si on n'a qu'un numéro
• n°^s si on liste plusieurs numéros. (Reste à savoir comment obtenir le « ^s ».

Answer 3

From personnal experience, I have always seen people using "N°" or "n°" (both using DEGREE SIGN U+00B0) written by hand, on computer or printed in books/newspapers.