Acronyms, index "see" and auxiliary files

Question

I'm using a few acronyms in my thesis, and I want them to appear in the alphabetical index as:

ACR, see acronym

acronym, iii, 5, 48

This is my code:

\documentclass[11pt,a4paper]{book}

\usepackage[nottoc,notlot,notlof]{tocbibind}
\usepackage{imakeidx}
\usepackage{bookmark} % includes hyperref
\usepackage[toc,acronym]{glossaries}

\makeindex[intoc]
\makeglossaries

\newacronym{fmea}{FMEA}{Fail\-ure Mode and Ef\-fect A\-nal\-y\-sis}

\begin{document}

    \frontmatter
    \tableofcontents
    
    \mainmatter
    Occurrence of the acronym \acrlong{FMEA}
    \index{FMEA}
    
    \backmatter
    \printglossary[type=\acronymtype,nonumberlist]
    \index{failure mode and effect analysis|see{FMEA}}
    \printindex
\end{document}

This code works perfectly but I have to declare each acronym twice (as newacronym and as index "see"). I introduced this command as a variant of \newacronym which also generates the corresponding \index voice:

\newcommand{\newacronymidx}[3]{
  \newacronym{#1}{#2}{#3}
  \index{\MakeLowercase{#3}|see #2}
}

\newacronym{fmea}{FMEA}{Fail\-ure Mode and Ef\-fect A\-nal\-y\-sis}

I have three problems:

1. the "ACR, see acronym" index entry appears at the beginning of the alphabetical index instead of its correct alphabetically-sorted position
2. now I get a page number after "ACR, see acronym", whose hyperlink refers to first page (the frontispiece, not included in this MWE)
3. for some weird reason I can't understand, FMEA becomes FEA (which does not appear anywhere in my code)

In this example, FMEA is defined with \newacronymidx, other acronyms with \newacronym and \index{acronym|see ACR}. The only wrong one is FMEA.

Question 1:

I think that the first two problems are related to the position of the \index command in the source (which is now in the preamble). Is there any way to create an auxiliary files, use \makeacronymidx to append a new line with the \index command to this file, and use \include{myAuxFile} right before \printindex?

Question 2:

Any idea about FMEA becoming FEA in the index? This does not happen with this MWE, but I can't post the full code here...

Thank you!

EDIT: solved by Nicola Talbot in the comments

\newcommand{\newacronymidx}[3]{
  \newacronym{#1}{#2}{#3}
  \index{#3@\MakeLowercase{#3}|see {#2}}
}

Answer 1

Summary of comments:

• A sort value is required when the indexed term contains formatting commands (as makeindex doesn't ignore LaTeX commands but treats them as a string starting with \).
• The see encap requires braces around the argument: |see FMEA becomes \see FMEA{1} which is effectively \see{F}{M}EA1, so the M is discarded and the page number appears.

So the definition needs to be:

\newcommand{\newacronymidx}[3]{%
  \newacronym{#1}{#2}{#3}%
  \index{#3@\MakeLowercase{#3}|see{#2}}%
}

Answer 2

If this could be helpful to anyone, here are two ways to index acronyms, with the corrections made by Nicola Talbot. This code allows to specify the sorting part as optional argument.

---

Method 1: acronym points to full text

\usepackage{etoolbox}

\newcommand{\newacronymidx}[4][]{ % rimanda acronimo a esteso
    \newacronym{#2}{#3}{#4}
    \ifstrempty{#1}
        { \index{#3|see{\MakeLowercase{#4}}} }
        { \index{#3|see{#1}} }
}

\newacronymidx{acr}{ACR}{Acronym}
\newacronymidx[qwerty]{abb}{ABB}{Abbreviation}

INDEX:
ABB, see qwerty
ACR, see acronym
acronym, 18
qwerty, 36, 58

A possible use could be:

\newacronymidx[control limits]{ucl}{UCL}{Upper Control Limit}

Index entry: UCL, see control limits

---

Method 2: full text points to acronym

\usepackage{etoolbox}

\newcommand{\newacronymidx}[4][]{ % rimanda esteso ad acronimo
    \newacronym{#2}{#3}{#4}
    \ifstrempty{#1}
    { \index{#4@\MakeLowercase{#4}|see{#3}} }
    { \index{#1|see{#3}} }
}

\newacronymidx{acr}{ACR}{Acronym}
\newacronymidx[qwerty]{abb}{ABB}{Abbreviation}

INDEX:
ABB, 36, 58
ACR, 18
acronym, see ACR
qwerty, see ABB

A possible use could be:

\newacronymidx[Western Electric rules]{wer}{WER}{Western Electric Rules}

Index entry: Western Electric rules, see WER

(I don't want Western Electric to be lowercased)