To make the numero sign, would N\textsuperscript{\underline{\scriptsize o}} be a valid alternative to \textnumero (from textcomp package)

Question

Regarding LaTeX: Numero sign ('№'), would

N\textsuperscript{\underline{\scriptsize o}}

be a valid alternative to \textnumero (from textcomp package)? I prefer a numero sign that matches the font used for the surrounding text, although this is apparently not the preference of some fontographers (see Times New Roman).

Answer 1

Taking a lead from the ALTERNATIVE APPROACH in my answer at Scots-Irish American surnames: Mc - how to achieve a range of aesthetically appealing raised-c with underscore?...

The optional argument sets the gap between the "o" and underscore.

\documentclass{article}
\usepackage{stackengine,graphicx}
\newcommand\No[1][.13ex]{%
  \setbox0=\hbox{\scalebox{.7}{o}}%
  \setbox2=\hbox{N}%
  N\kern-.05em\stackengine{\dimexpr\ht0-\ht2+#1}{\belowbaseline[-\ht2]{\copy0}}%
    {\rule[-.13ex]{.7\wd0}{.13ex}}%
    {U}{c}{F}{F}{L}%
}

\begin{document}
\No 3

\LARGE\No[.2ex]3

\sffamily

\No 3

\normalsize \No 3
\end{document}

Answer 2

textcomp just takes glyph 155 (octal 233) from TS1 in computer modern, which gives the symbol you don't like.

See e.g. the LaTeX font encodings document; the relevant page is below.

And no, I don't have any objection to your choice, but as cfr observes, this glyph is part of the font.

Answer 3

In response to the comment, showing the plain, manually-constructed, form in blue (without any additional kerning, raiseboxes etc), to compare against the font designer's version:

Legacy fonts would require much more work (TS1 vs T1 encodings, kerning, resizes, etc):

MWE

\documentclass{article}
\usepackage[table]{xcolor}
\usepackage{fontspec}
\setmainfont{Noto Serif}
\newcommand\nhead{\rowcolor{blue!12}}
\newcommand\propsol{{\color{blue}N\textsuperscript{\underline{\scriptsize o}}}}
\newcommand\legpropsol{{\usefont{T1}{lmr}{m}{n}\color{blue}[N\textsuperscript{\underline{\scriptsize o}}]}}
\newcommand\mytext{text № [\propsol] 3 text}
\newfontfamily\ffonta{Book Antiqua}
%\newfontfamily\ffontb{Commissioner-Regular.ttf}
\newfontfamily\ffontc{Cormorant Garamond}
\newfontfamily\ffontd{Cormorant Infant}
\newfontfamily\ffonte{Cormorant SC}
\newfontfamily\ffontf{DejaVu Sans}
\newfontfamily\ffontg{DejaVu Sans Mono}
\newfontfamily\ffonth{DejaVu Serif}
\newfontfamily\ffonti{Doulos SIL}
%\newfontfamily\ffontj{Exo 2}
\newfontfamily\ffontk{FreeMono}
\newfontfamily\ffontl{FreeSans}
\newfontfamily\ffontm{FreeSerif}
\newfontfamily\ffontn{Gentium Plus}
\newfontfamily\ffonto{IBM Plex Mono}
\newfontfamily\ffontp{IBM Plex Sans}
\newfontfamily\ffontq{IBM Plex Serif}
\newfontfamily\ffontr{Liberation Mono}
\newfontfamily\ffonts{Liberation Sans}
\newfontfamily\ffontt{Liberation Serif}
\newfontfamily\ffontu{Linux Biolinum G}
\newfontfamily\ffontv{Linux Libertine Display G}
\newfontfamily\ffontw{Linux Libertine G}
\newfontfamily\ffontx{Noto Mono}
\newfontfamily\ffonty{Noto Sans}
\newfontfamily\ffontz{Noto Sans Display}
\newfontfamily\ffontaa{Noto Serif}
\newfontfamily\ffontab{Noto Serif Display}
\newfontfamily\ffontac{Roboto}
\newfontfamily\ffontad{Source Code Pro}
\newfontfamily\ffontae{Source Sans Pro}
\newfontfamily\ffontaf{Source Serif Pro}
\newcommand\legfont[2]{%
\usefont{T1}{#1}{m}{#2}text \usefont{TS1}{#1}{m}{#2}\char"9B  \legpropsol \usefont{T1}{#1}{m}{#2}\ 3 text
}
\begin{document}
Unicode glyph [plus manually constructed form]
U+2116 № [\verb|N\textsuperscript{\underline{\scriptsize o}}|]
\bigskip
\noindent\begin{tabular}{lll}
\nhead Font & Upright & Italic \
Book Antiqua & \ffonta\mytext & \ffonta\textit{\mytext} \
%Commissioner & \ffontb\mytext & \ffontb\textit{\mytext} \
Cormorant Garamond & \ffontc\mytext & \ffontc\textit{\mytext} \
Cormorant Infant &  & \ffontd\textit{\mytext} \
%Cormorant SC & \ffonte\mytext & \
DejaVu Sans & \ffontf\mytext & \ffontf\textit{\mytext} \
DejaVu Sans Mono & \ffontg\mytext & \ffontg\textit{\mytext} \
DejaVu Serif & \ffonth\mytext & \ffonth\textit{\mytext} \
Doulos SIL & \ffonti\mytext &  \
%Exo 2 & \ffontj\mytext & \ffontj\textit{\mytext} \
FreeMono & \ffontk\mytext & \ffontk\textit{\mytext} \
FreeSans & \ffontl\mytext & \ffontl\textit{\mytext} \
FreeSerif & \ffontm\mytext & \ffontm\textit{\mytext} \
Gentium Plus & \ffontn\mytext & \ffontn\textit{\mytext} \
IBM Plex Mono & \ffonto\mytext & \ffonto\textit{\mytext} \
IBM Plex Sans & \ffontp\mytext & \ffontp\textit{\mytext} \
IBM Plex Serif & \ffontq\mytext & \ffontq\textit{\mytext} \
Liberation Mono & \ffontr\mytext & \ffontr\textit{\mytext} \
Liberation Sans & \ffonts\mytext & \ffonts\textit{\mytext} \
Liberation Serif & \ffontt\mytext & \ffontt\textit{\mytext} \
Linux Biolinum G & \ffontu\mytext & \ffontu\textit{\mytext} \
Linux Libertine Display G & \ffontv\mytext & \
Linux Libertine G & \ffontw\mytext & \ffontw\textit{\mytext} \
Noto Mono & \ffontx\mytext &  \
Noto Sans & \ffonty\mytext & \ffonty\textit{\mytext} \
Noto Sans Display & \ffontz\mytext & \ffontz\textit{\mytext} \
Noto Serif & \ffontaa\mytext & \ffontaa\textit{\mytext} \
Noto Serif Display & \ffontab\mytext & \ffontab\textit{\mytext} \
Roboto & \ffontac\mytext & \ffontac\textit{\mytext} \
Source Code Pro & \ffontad\mytext & \ffontad\textit{\mytext} \
Source Sans Pro & \ffontae\mytext & \ffontae\textit{\mytext} \
Source Serif Pro & \ffontaf\mytext &  \
\end{tabular}
\newpage
\usefont{T1}{lmr}{m}{n}Legacy fonts: slot 9B of TS1 encoding:  {\usefont{TS1}{lmr}{m}{n}\char"9B}
\bigskip
\begin{tabular}{lll}
\nhead Font family & Upright & Italic \
lmr & \legfont{lmr}{n} & \legfont{lmr}{it} \
qzc &  & \legfont{qzc}{it} \
qtm & \legfont{qtm}{n} & \legfont{qtm}{it} \
qpl & \legfont{qpl}{n} & \legfont{qpl}{it} \
qhv & \legfont{qhv}{n} & \legfont{qhv}{it} \
qcs & \legfont{qcs}{n} & \legfont{qcs}{it} \
qcr & \legfont{qcr}{n} & \legfont{qcr}{it} \
qbk & \legfont{qbk}{n} & \legfont{qbk}{it} \
qag & \legfont{qag}{n} & \legfont{qag}{it} \
stix2 & \legfont{stix2}{n} & \legfont{stix2}{it} \
\end{tabular}
\end{document}

---

Original answer

The abbreviation for numero seems to be like ℜ ℞ ℃ Å ℮ ℅ ℊ, in the sense of having its own typesetting tradition, which means that making it match the surrounding text could surprise some readers.

Having said that, it is a rarely used glyph and does seem to have some free-form quality about it, almost exotic, in terms of being a little bit different from the surroundings (especially in the serif fonts) but not too different.

Unicode font sample:

Legacy font sample:

MWE

\documentclass{article}
\usepackage[table]{xcolor}
\usepackage{fontspec}
\setmainfont{Noto Serif}
\newcommand\nhead{\rowcolor{blue!12}}
\newcommand\mytext{text № 3 text}
\newfontfamily\ffonta{Book Antiqua}
%\newfontfamily\ffontb{Commissioner-Regular.ttf}
\newfontfamily\ffontc{Cormorant Garamond}
\newfontfamily\ffontd{Cormorant Infant}
\newfontfamily\ffonte{Cormorant SC}
\newfontfamily\ffontf{DejaVu Sans}
\newfontfamily\ffontg{DejaVu Sans Mono}
\newfontfamily\ffonth{DejaVu Serif}
\newfontfamily\ffonti{Doulos SIL}
%\newfontfamily\ffontj{Exo 2}
\newfontfamily\ffontk{FreeMono}
\newfontfamily\ffontl{FreeSans}
\newfontfamily\ffontm{FreeSerif}
\newfontfamily\ffontn{Gentium Plus}
\newfontfamily\ffonto{IBM Plex Mono}
\newfontfamily\ffontp{IBM Plex Sans}
\newfontfamily\ffontq{IBM Plex Serif}
\newfontfamily\ffontr{Liberation Mono}
\newfontfamily\ffonts{Liberation Sans}
\newfontfamily\ffontt{Liberation Serif}
\newfontfamily\ffontu{Linux Biolinum G}
\newfontfamily\ffontv{Linux Libertine Display G}
\newfontfamily\ffontw{Linux Libertine G}
\newfontfamily\ffontx{Noto Mono}
\newfontfamily\ffonty{Noto Sans}
\newfontfamily\ffontz{Noto Sans Display}
\newfontfamily\ffontaa{Noto Serif}
\newfontfamily\ffontab{Noto Serif Display}
\newfontfamily\ffontac{Roboto}
\newfontfamily\ffontad{Source Code Pro}
\newfontfamily\ffontae{Source Sans Pro}
\newfontfamily\ffontaf{Source Serif Pro}
\newcommand\legfont[2]{%
\usefont{T1}{#1}{m}{#2}text \usefont{TS1}{#1}{m}{#2}\char"9B\usefont{T1}{#1}{m}{#2}\ 3 text
}
\begin{document}
U+2116 №
\bigskip
\noindent\begin{tabular}{lll}
\nhead Font & Upright & Italic \
Book Antiqua & \ffonta\mytext & \ffonta\textit{\mytext} \
%Commissioner & \ffontb\mytext & \ffontb\textit{\mytext} \
Cormorant Garamond & \ffontc\mytext & \ffontc\textit{\mytext} \
Cormorant Infant &  & \ffontd\textit{\mytext} \
%Cormorant SC & \ffonte\mytext & \
DejaVu Sans & \ffontf\mytext & \ffontf\textit{\mytext} \
DejaVu Sans Mono & \ffontg\mytext & \ffontg\textit{\mytext} \
DejaVu Serif & \ffonth\mytext & \ffonth\textit{\mytext} \
Doulos SIL & \ffonti\mytext &  \
%Exo 2 & \ffontj\mytext & \ffontj\textit{\mytext} \
FreeMono & \ffontk\mytext & \ffontk\textit{\mytext} \
FreeSans & \ffontl\mytext & \ffontl\textit{\mytext} \
FreeSerif & \ffontm\mytext & \ffontm\textit{\mytext} \
Gentium Plus & \ffontn\mytext & \ffontn\textit{\mytext} \
IBM Plex Mono & \ffonto\mytext & \ffonto\textit{\mytext} \
IBM Plex Sans & \ffontp\mytext & \ffontp\textit{\mytext} \
IBM Plex Serif & \ffontq\mytext & \ffontq\textit{\mytext} \
Liberation Mono & \ffontr\mytext & \ffontr\textit{\mytext} \
Liberation Sans & \ffonts\mytext & \ffonts\textit{\mytext} \
Liberation Serif & \ffontt\mytext & \ffontt\textit{\mytext} \
Linux Biolinum G & \ffontu\mytext & \ffontu\textit{\mytext} \
Linux Libertine Display G & \ffontv\mytext & \
Linux Libertine G & \ffontw\mytext & \ffontw\textit{\mytext} \
Noto Mono & \ffontx\mytext &  \
Noto Sans & \ffonty\mytext & \ffonty\textit{\mytext} \
Noto Sans Display & \ffontz\mytext & \ffontz\textit{\mytext} \
Noto Serif & \ffontaa\mytext & \ffontaa\textit{\mytext} \
Noto Serif Display & \ffontab\mytext & \ffontab\textit{\mytext} \
Roboto & \ffontac\mytext & \ffontac\textit{\mytext} \
Source Code Pro & \ffontad\mytext & \ffontad\textit{\mytext} \
Source Sans Pro & \ffontae\mytext & \ffontae\textit{\mytext} \
Source Serif Pro & \ffontaf\mytext &  \
\end{tabular}
\newpage
\usefont{T1}{lmr}{m}{n}Legacy fonts: slot 9B of TS1 encoding:  {\usefont{TS1}{lmr}{m}{n}\char"9B}
\bigskip
\begin{tabular}{lll}
\nhead Font family & Upright & Italic \
lmr & \legfont{lmr}{n} & \legfont{lmr}{it} \
qzc &  & \legfont{qzc}{it} \
qtm & \legfont{qtm}{n} & \legfont{qtm}{it} \
qpl & \legfont{qpl}{n} & \legfont{qpl}{it} \
qhv & \legfont{qhv}{n} & \legfont{qhv}{it} \
qcs & \legfont{qcs}{n} & \legfont{qcs}{it} \
qcr & \legfont{qcr}{n} & \legfont{qcr}{it} \
qbk & \legfont{qbk}{n} & \legfont{qbk}{it} \
qag & \legfont{qag}{n} & \legfont{qag}{it} \
stix2 & \legfont{stix2}{n} & \legfont{stix2}{it} \
\end{tabular}
\end{document}