# Hyperref warning which doesn't affect the output of the PDF

I have encountered a `hyperref` warning but there are no visible negative consequences. Additionally, LaTeX complete without a complaint. I only found the warning by looking at the `.log` file.

``````Package hyperref Warning: Difference (2) between bookmark levels is greater
(hyperref)                than one, level fixed on input line 2366.
``````

and

``````Package hyperref Warning: Token not allowed in a PDF string (PDFDocEncoding):
(hyperref)                removing `math shift' on input line 2206.
``````

and

``````Package hyperref Warning: Token not allowed in a PDF string (PDFDocEncoding):
(hyperref)                removing `superscript' on input line 2200.
``````

Does anyone know what this means?

Those lines don't correspond to references either.

-

``````Package hyperref Warning: Difference (2) between bookmark levels is greater
(hyperref)                than one, level fixed on input line 2366.
``````

The first warning can be caused by missing section levels. For example, a `\subsubsection` following a `\section`. If this is intentional, then I recommend package `bookmark`. It implements the bookmark managing in a robuster way that can deal with missing section levels. It is loaded after package `hyperref`:

``````\usepackage{hyperref}
\usepackage{bookmark}
``````

``````Package hyperref Warning: Token not allowed in a PDF string (PDFDocEncoding):
(hyperref)                removing `math shift' on input line 2206.
``````

This means, you have `\$` in the bookmark. Math is typeset by TeX that is not available by PDF viewers. If the bookmark title is ok, then you can ignore the warning. Otherwise an alternative string representation for the bookmark title can be given by `\texorpdfstring`:

``````\texorpdfstring{\$E=mc^2\$}{E=mc\texttwosuperior}
``````

For larger support of math symbols I recommend Unicode encoding for bookmark titles, set by option `unicode` or `pdfencoding=auto`, and the new option `psdextra`:

``````\usepackage[pdfencoding=auto,psdextra]{hyperref}
``````
-
I added `\usepackage{bookmark}` and the options to `hyperref`. I now have an option clash with `hypcap`. In my preamble, I have `hyperref` then `hypcap` with the option all. –  dustin Jun 14 '13 at 0:10
Load package `bookmark` after `hyperref`, because `bookmark` requires `hyperref` and loads it without options. This causes an option clash, if `hyperref` is loaded later with options. –  Heiko Oberdiek Jun 14 '13 at 0:18
–  Werner Jun 14 '13 at 0:26