# Is there a generic dummy command?

I would like to add in the title field of some bib entries a dummy command which I can redefine to force e.g. a linebreak in certain cases. I need a command which normally doesn't do anything, doesn't rely on some specific package (so that the bib-file doesn't break when used without the package), which isn't used elsewhere and which I can safely redefine without breaking something.

I looked up latex.ltx but couldn't find anything suitable. Has someone an idea what I could use if I don't want to clutter the bib with `\csname adummycommand\endcsname`?

-

Longer answer, as an alternative to the slightly obscure

``````\csname adummycommand\endcsname
``````

You could use

``````\adummy
``````

together with

``````@PREAMBLE{{\providecommand\adummy{}}}
``````
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That would be quite okay but biblatex/biber don't like `@PREAMBLE{\providecommand\adummy{}}`. I get `syntax error: found "dummy"`. –  Ulrike Fischer Jun 6 at 17:20
I usually redefine some command before/after `\printindex`, `\tableofcontents`, `\bibliography` etc. It suits me well for forcing line breaks. For rather complicated things I define two independent commands for the same typesetted material. The disadvantage is it can lead to mistyping errors. –  Malipivo Jun 7 at 5:53
@Malipivo that's fine in a personal project but harder to arrange if you are publishing "public" bib databases –  David Carlisle Jun 7 at 8:56
@DavidCarlisle: I put to much trust in your example ;-). Even with bibtex it wouldn't work: There is a layer of braces missing. One needs to use `@PREAMBLE{{\providecommand\adummy{}}}` or `@PREAMBLE{"\providecommand\adummy{}"}`. With this correction it works with biber too. And the definition is seen by the document. Now I only have to think about a good name ;-). –  Ulrike Fischer Jun 7 at 9:35
@UlrikeFischer oops I fixed the answer;-) –  David Carlisle Jun 7 at 9:56