Please note that the backslash means start of a command in _doxygen_, so `\The` will be assumed to be a command (which does not exist, of course), and won't make it to the output html.

It might be helpful to consult the [doxygen manual](http://www.stack.nl/~dimitri/doxygen/manual/index.html). Additionally, you can run `make doc` locally to see the output as it will appear on the PCL online documentation site.