%
% This file presents the 'authoryear-ibid' style
%
\documentclass[a4paper]{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[american]{babel}
\usepackage{csquotes}
\usepackage[style=authoryear-ibid,backend=biber]{biblatex}
\usepackage{hyperref}
\addbibresource{biblatex-examples.bib}
% Some generic settings:
\newcommand{\cmd}[1]{\texttt{\textbackslash #1}}
\setlength{\parindent}{0pt}
\newenvironment{bibsample}
  {\trivlist\samepage
   \setlength{\itemsep}{0pt}}
  {\endtrivlist}
\begin{document}

\section*{The \texttt{authoryear-ibid} style}

This citation style is a variant of the \texttt{authoryear} style.
Immediately repeated citations are replaced by the abbreviation
`ibidem' unless the citation is the first one on the current page or
double page spread (depending on the setting of the
\texttt{pagetracker} package option). This style is intended for
citations given in footnotes.

\subsection*{Additional package options}

\subsubsection*{The \texttt{ibidpage} option}

The scholarly abbreviation \emph{ibidem} is sometimes taken to mean
both `same author~+ same title' and `same author~+ same title~+ same
page' in traditional citation schemes. By default, this is not the
case with this style because it may lead to ambiguous citations.
With \texttt{ibidpage=true} a page range postnote will be suppressed
in an \emph{ibidem} citation if the last citation was to the same
page range. With \texttt{ibidpage=false} the postnote is not omitted.
Citations to different page ranges than the previous always produce
the page ranges with either setting.
The default setting is \texttt{ibidpage=false}.

Consider the following example citations
\begin{verbatim}
\cite[378]{sigfridsson}
\cite[378]{sigfridsson}
\cite[12]{worman}
\cite[13]{worman}
\end{verbatim}
%
If \texttt{ibidpage} is set to \texttt{true}, the citations
come out as
\begin{quote}
Sigfridsson and Ryde 1998, p.~378

ibid.

Worman 2002, p.~12

ibid., p.~13
\end{quote}
%
The result for \texttt{ibidpage=false} is
\begin{quote}
Sigfridsson and Ryde 1998, p.~378

ibid., p.~378

Worman 2002, p.~12

ibid., p.~13
\end{quote}

\subsubsection*{The \texttt{dashed} option}

By default, this style replaces recurrent authors/editors in the
bibliography by a dash so that items by the same author or editor
are visually grouped. This feature is controlled by the package
option \texttt{dashed}. Setting \texttt{dashed=false} in the
preamble will disable this feature. The default setting is
\texttt{dashed=true}.

\subsubsection*{The \texttt{mergedate} option}

Since this style prints the date label after the author/editor in the
bibliography, there are effectively two dates in the bibliography:
the full date specification (e.g., \enquote{2001}, \enquote{June
2006}, \enquote{5th~Jan. 2008}, whose format is controlled by the
\texttt{date} option) and the date label (e.g., \enquote{2006a},
whose format is controlled with the \texttt{labeldate} option),
as found in citations. The \texttt{mergedate} option controls whether
or not date specifications are merged with the date label.
This option is best explained by example. Note that
it only affects the bibliography. Citations use the date label only.

\begin{bibsample}
\item Doe 2000
\item Doe 2003a
\item Doe 2003b
\item Doe 2006a
\item Doe 2006b
\item Doe 2017
\end{bibsample}

\texttt{mergedate=false} strictly separates the date specification
(following \texttt{date}) from the date label (following \texttt{labeldate}).
The year will always be printed twice:

\begin{bibsample}
\item Doe, John (2000). \emph{Book~1}. Location: Publisher, 2000.
\item Doe, John (2003a). \emph{Book~2}. Location: Publisher, 2003.
\item Doe, John (2003b). \emph{Book~3}. Location: Publisher, 2003.
\item Doe, John (2006a). \enquote{Article~1}. In: \emph{Monthly Journal} 25.6
(June~2006), pp.~70--85.
\item Doe, John (2006b). \enquote{Article~2}. In: \emph{Quarterly Journal} 14.3
(Fall~2006), pp.~5--25.
\item Doe, John (2017). \emph{Webpage}. 7th Aug. 2017.
\end{bibsample}

\texttt{mergedate=minimum} omits the date whenever the full date
and the date label have exactly the same precision (date-time granularity).

\begin{bibsample}
\item Doe, John (2000). \emph{Book~1}. Location: Publisher.
\item Doe, John (2003a). \emph{Book~2}. Location: Publisher, 2003.
\item Doe, John (2003b). \emph{Book~3}. Location: Publisher, 2003.
\item Doe, John (2006a). \enquote{Article~1}. In: \emph{Monthly Journal} 25.6
(June~2006), pp.~70--85.
\item Doe, John (2006b). \enquote{Article~2}. In: \emph{Quarterly Journal} 14.3
(Fall~2006), pp.~5--25.
\item Doe, John (2017). \emph{Webpage}. 7th Aug. 2017.
\end{bibsample}

\texttt{mergedate=basic} is similar in concept but more economical.
It will also omit the date if it differs from the date label only by
\texttt{extradate}.

\begin{bibsample}
\item Doe, John (2000). \emph{Book~1}. Location: Publisher.
\item Doe, John (2003a). \emph{Book~2}. Location: Publisher.
\item Doe, John (2003b). \emph{Book~3}. Location: Publisher.
\item Doe, John (2006a). \enquote{Article~1}. In: \emph{Monthly Journal} 25.6
(June~2006), pp.~70--85.
\item Doe, John (2006b). \enquote{Article~2}. In: \emph{Quarterly Journal} 14.3
(Fall~2006), pp.~5--25.
\item Doe, John (2017). \emph{Webpage}. 7th Aug. 2017.
\end{bibsample}

\texttt{mergedate=compact} merges all date specifications with the
date labels. The merged date is printed in \texttt{date} format,
not \texttt{labeldate}, even if it is printed in the position of
the date label. The \texttt{issue} field is still treated specially:

\begin{bibsample}
\item Doe, John (2000). \emph{Book~1}. Location: Publisher.
\item Doe, John (2003a). \emph{Book~2}. Location: Publisher.
\item Doe, John (2003b). \emph{Book~3}. Location: Publisher.
\item Doe, John (June 2006a). \enquote{Article~1}. In: \emph{Monthly Journal} 25.6, pp.~70--85.
\item Doe, John (2006b). \enquote{Article~2}. In: \emph{Quarterly Journal} 14.3
(Fall), pp.~5--25.
\item Doe, John (7th Aug. 2017).\emph{Webpage}.
\end{bibsample}

\texttt{mergedate=maximum} strives for maximum compactness.
Like \texttt{mergedate=compact} this option merges the date
into the date label.
Even the \texttt{issue} field is merged with the date label:

\begin{bibsample}
\item Doe, John (2000). \emph{Book~1}. Location: Publisher.
\item Doe, John (2003a). \emph{Book~2}. Location: Publisher.
\item Doe, John (2003b). \emph{Book~3}. Location: Publisher.
\item Doe, John (June 2006a). \enquote{Article~1}. In: \emph{Monthly Journal} 25.6, pp.~70--85.
\item Doe, John (Fall 2006b). \enquote{Article~2}. In: \emph{Quarterly Journal} 14.3, pp.~5--25.
\item Doe, John (7th Aug. 2017).\emph{Webpage}.
\end{bibsample}

\texttt{mergedate=true} is an alias for \texttt{mergedate=compact}.
This is the default setting.

\subsection*{Hints}

If you want terms such as \emph{ibidem} to be printed in italics,
redefine \cmd{mkibid} as follows:

\begin{verbatim}
\renewcommand*{\mkibid}{\emph}
\end{verbatim}

\subsection*{\cmd{footcite} examples}

This is just filler text.\footcite{companion}
% Immediately repeated citations are replaced by the
% abbreviation 'ibidem'...
This is just filler text.\footcite{companion}
\clearpage
% ... unless the citation is the first one on the current page
% or double page spread (depending on the setting of the
% 'pagetracker' package option).
This is just filler text.\footcite[55]{companion}
This is just filler text.\footcite[55]{companion}

\clearpage
\printbibliography

\end{document}
