# biber - warning about non-ascii characters

Biber gives me the following warning:

WARN - The entry 'csorgo__sandor:10' has characters
which cannot be encoded in 'ascii'. Recoding problematic
characters into macros.


Is this anything to worry about? If not, why the warning?

\documentclass{article}
\usepackage[url=false,citestyle=verbose,backend=biber]{biblatex}

\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
@article{csorgo__sandor:10,
year={2008},
author={K\'{e}rchy, Cz\'{e}dli, G. and Hajnal, P. and others},
title={{S}\'{a}ndor {C}s\"{o}rg\H{o}, 1947-2008},
journal={Acta Sci. Math. (Szeged)},
pages={3-5},
volume={74},
}
\end{filecontents}

\begin{document}

\nocite{*}
\printbibliography
\end{document}

• It is only a warning. biber encodes to UTF8 and then decodes back to ascii, but has to use macros for some of the accents. – Andrew Swann Sep 18 '14 at 14:15

To get rid off the warning you can change the input code to utf8 for your .tex-file.

With the following changed MWE I have no warnings or errors from biber and only one warning with the .tex-file (because package filecontents generates this warning). I marked the changes with %!!!!!!!!

\RequirePackage{filecontents}
\begin{filecontents*}{\jobname.bib}
@article{csorgo__sandor:10,
year    = {2008},
author  = {K\'{e}rchy, Cz\'{e}dli, G. and Hajnal, P. and others},
title   = {{S}\'{a}ndor {C}s\"{o}rg\H{o}, 1947--2008},
journal = {Acta Sci. Math. (Szeged)},
pages   = {3--5},
volume  = {74},
}
\end{filecontents*}

\documentclass{article}
\usepackage[utf8]{inputenc}    % utf8 support       %!!!!!!!!!!!!!!!!!!!!
\usepackage[T1]{fontenc}       % code for pdf file  %!!!!!!!!!!!!!!!!!!!!
\usepackage[url=false,citestyle=verbose,backend=biber]{biblatex}

• so it's a compulsory to use \usepackage[utf8]{inputenc} for compiling non-ASCII characters in bibliography? Then what's the advantage of using XeLaTeX and pdfLaTeX? – Ooker Dec 15 '17 at 6:05