# Handling overflows in biblatex bibliographies

I'm finally making the transition to `biblatex`. This is a remarkable package, and has allowed me to cut out quite a bit of old code I used to use to handle eprints, DOIs, crossref mapping problems, etc. Wow!

One challenge is that I am less sure how to "fine-tune" the results of the system. One recent issue that has come up is how to handle overfull bibliography items. Consider the following example, typeset by `biblatex`/pdfLaTeX in the middle of a bibliography:

This seems to be a challenge: I don't have "direct" control of the typesetting--as I understand, it is produced on-the-fly by macros applied to the .bbl file. To make matters worse, it seems like the right solution is to fiddle with `biblatex`'s DOI code, which seems very intimidating.

My favorite solution would be a way to have `biblatex` break this DOI in the middle. No one's going to read it anyhow. Is this possible?

Failing that, I suppose I could manually edit the .bbl and add `\tolerance` changes right before this entry, but it seems this would have to be done each time I compile the file.

Any suggestions very appreciated.

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I thought this solution below was nice. It puts the DOI (URL...) information on a new line. Somehow, it gets things well organised: tex.stackexchange.com/questions/29802/… –  pluton Apr 6 '12 at 2:21
@pluton : I like that. Thanks for the pointer! –  acr Apr 6 '12 at 12:43

## 1 Answer

Since version 1.7 of `biblatex`, numbers are no longer breakpoints, but can be re-instated with the `biburlnumpenalty` counter.

``````\setcounter{biburlnumpenalty}{100}
``````

in your preamble should allow a break in the DOI.

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That does it! Gee, does biblatex have an option for everything? Thank you! –  acr Apr 6 '12 at 12:37