%%
%% The LaTeX Companion, 3ed
%%
%% Example 16-7-40 on page II-568 in "Changing format directives".
%%
%% Copyright (C) 2022 Frank Mittelbach
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3c
%% of this license or (at your option) any later version.
%%
%% See https://www.latex-project.org/lppl.txt for details.
%%

\documentclass{tlc3exa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{111.0pt}
%
  \setlength\parindent{0pt}
%  Use biber program

%StartShownPreambleCommands
\usepackage{biblatex}
\addbibresource{tlc.bib}
\DeclareNameFormat{mynameformat}
   {\thelistcount/\theliststop:
    \namepartgiveni~\namepartfamily~(\namepartfamilyi)%
    \ifnumgreater{\value{listcount}}{\value{liststop}-1}%
                 {}{\\}%      add a linebreak between names
   }
%StopShownPreambleCommands

\begin{document}
\citename{LGC97}[mynameformat]{author} \\[3pt]
\citename{EP92}[mynameformat]{editor}
\end{document}