Including shorthand abbreviations into bibliography (biblatex)

Question

Instead of generating a list of abbreviations, I want the abbreviations to be included in the bibliography as it is done in the following example with ESSJ (this list is not generated by LaTeX):

Using the following code as an example,

\documentclass{article}
\usepackage{polyglossia}
\setmainlanguage{american}
\usepackage[style=ext-authoryear-comp,articlein=false,innamebeforetitle=false,dashed=false]{biblatex}
\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
@book{Corbett2000Number,
    author = {Corbett, Greville G.},
    date = {2000},
    location = {Cambridge},
    publisher = {Cambridge University Press},
    title = {Number}
}
@book{BezlajESSJ,
    author = {Bezlaj, France},
    date = {1977/2007},
    location = {Ljubljana},
    title = {Etimološki slovar slovenskega jezika},
    shorthand = {ESSJ}
}
\end{filecontents}
\addbibresource{\jobname.bib}
\begin{document}
Something (\cite{Corbett2000Number}, \cite{BezlajESSJ}).
\printbibliography
\end{document}

I get:

but would like to get:

I'm using XeLaTeX and biblatex with the ext-authoryear-comp style. I would kindly ask for pointers on how this might be achievable.

Answer 1

This is a job for the begentry bibmacro, which can be used to insert arbitrary stuff at the beginning of an entry.

\documentclass{article}
\usepackage{polyglossia}
\setmainlanguage{american}
\usepackage[
  style=ext-authoryear-comp,
  articlein=false,
  innamebeforetitle=false,
  dashed=false,
]{biblatex}
\renewbibmacro{begentry}{%
  \printfield{shorthand}%
  \printunit{\addspace=\space}%
}
\begin{filecontents}{\jobname.bib}
@book{Corbett2000Number,
  author    = {Corbett, Greville G.},
  date      = {2000},
  location  = {Cambridge},
  publisher = {Cambridge University Press},
  title     = {Number},
}
@book{BezlajESSJ,
  author    = {Bezlaj, France},
  date      = {1977/2007},
  location  = {Ljubljana},
  title     = {Etimološki slovar slovenskega jezika},
  shorthand = {ESSJ},
}
\end{filecontents}
\addbibresource{\jobname.bib}
\begin{document}
Something \autocite{Corbett2000Number,BezlajESSJ}.
\printbibliography
\end{document}