Biblatex how to reduce spacing before and after a prenote?

Question

I'm using Biblatex and biber. How is it possible to reduce the spacing before and after a pre note?

Edited:

Here is as MWE:

\documentclass{article}
\usepackage{filecontents}
\begin{filecontents*}{\jobname.bib}
@THESIS{a,
  AUTHOR =  {Myself},
  TITLE = {Me, myself and I},
  Institution = {My University},
  type = {Ph.D. thesis},
  date = {2010-11-25}
}
%  year = {2010} 
\end{filecontents*}
\usepackage[backend=biber,defernumbers=true,sorting=ydnt]{biblatex}
\addbibresource{\jobname.bib}
\defbibnote{AA}{\underline{Here is a prenote}}

\begin{document}
Hello world.

    \nocite{*}
    \printbibliography[heading=none,resetnumbers=true,prenote=AA]
    \printbibliography[heading=none,resetnumbers=true,prenote=AA]
    \printbibliography[heading=none,resetnumbers=true,prenote=AA]
\end{document}

@moewe is right. The spacing before a prenote is handled by what is happening before. If there is no space between "Hello World" and \nocite, then the prenote is in the same paragraph as "Hello World".

So I reformulate. Inside a biblio (like between the second and the third citations) in the MWE, how can I set the spacing before a prenote.

How can I set the spacing after a prenote?

Answer 1

The vertical space is just the space before and after the first and last item of the bibliography. But you can manipulate it, e.g., with \vskip either in the note or between the \printbibliography. The horizontal space before the note is the normal paragraph indent and can be removed using \noindent again either between the \printbibliography or in the note:

\documentclass{article}
\usepackage{filecontents}
\begin{filecontents*}{\jobname.bib}
@THESIS{a,
  AUTHOR =  {Myself},
  TITLE = {Me, myself and I},
  Institution = {My University},
  type = {Ph.D. thesis},
  date = {2010-11-25}
}
%  year = {2010} 
\end{filecontents*}
\usepackage[backend=biber,defernumbers=true,sorting=ydnt]{biblatex}
\addbibresource{\jobname.bib}
\defbibnote{AA}{\underline{Here is a prenote}}
\defbibnote{BB}{\vskip-2ex\noindent\underline{Here is a prenote}\vskip-1ex}

\begin{document}
Hello world.

    \nocite{*}
    \printbibliography[heading=none,resetnumbers=true,prenote=AA]
    \vskip -2ex\noindent
    \printbibliography[heading=none,resetnumbers=true,prenote=AA]
    \printbibliography[heading=none,resetnumbers=true,prenote=BB]
\end{document}

The example shows both methods.