我认为我在acro-package 中发现了一个错误，该错误在使用 -option 时出现single。考虑以下 MWE：
\documentclass[]{article}
\usepackage[single]{acro}
\DeclareAcronym{HMM}{%
short=HMM,
long=Hidden-Markov-Modell
}
\DeclareAcronym{HMM2}{%
short=HMM,
long=Hidden-Markov-Modell,
long-plural-form=Hidden-Markov-Modells
}
\DeclareAcronym{PCA}{%
short=PCA,
long=Principle-Component-Analysis
}
\begin{document}
\noindent%
\acp{HMM} -- \emph{the plural form is not used}\\
\acp{HMM2} -- \emph{the plural form is used}\\
\acp{PCA} -- \emph{the plural form is used}\\
\ac{PCA}
\end{document}
复数形式的输出取决于您使用的选项。在上面的例子中HMM2（为其定义了完整的复数形式），虽然只使用了一次，但确实有效，而HMM没有。PCA确实有效，因为它使用了多次。
上述 MWE 的输出：
输出\listfiles：
*File List*
article.cls 2014/09/29 v1.4h Standard LaTeX document class
size10.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
acro.sty 2017/01/22 v2.7a Typeset Acronyms
expl3.sty 2017/04/01 L3 programming layer (loader)
expl3-code.tex 2017/04/01 L3 programming layer
l3pdfmode.def 2017/03/18 v L3 Experimental driver: PDF mode
xparse.sty 2017/04/01 L3 Experimental document command parser
l3keys2e.sty 2017/04/01 LaTeX2e option processing using LaTeX3 keys
xtemplate.sty 2017/04/01 L3 Experimental prototype document functions
etoolbox.sty 2017/01/02 v2.4 e-TeX tools for LaTeX (JAW)
zref-abspage.sty 2016/05/21 v2.26 Module abspage for zref (HO)
zref-base.sty 2016/05/21 v2.26 Module base for zref (HO)
ltxcmds.sty 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
infwarerr.sty 2016/05/16 v1.4 Providing info/warning/error messages (HO)
kvsetkeys.sty 2016/05/16 v1.17 Key value parser (HO)
etexcmds.sty 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
ifluatex.sty 2016/05/16 v1.4 Provides the ifluatex switch (HO)
kvdefinekeys.sty 2016/05/16 v1.4 Define keys (HO)
pdftexcmds.sty 2017/03/19 v0.25 Utility functions of pdfTeX for LuaTeX (HO)
ifpdf.sty 2017/03/15 v3.2 Provides the ifpdf switch
auxhook.sty 2016/05/16 v1.4 Hooks for auxiliary files (HO)
atbegshi.sty 2016/06/09 v1.18 At begin shipout hook (HO)
translations.sty 2017/03/05 v1.5a internationalization of LaTeX2e packages (
CN)
scrlfile.sty 2017/01/03 v3.22 KOMA-Script package (loading files)
translations-basic-dictionary-english.trsl (english translation file `transl
ations-basic-dictionary')
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