In the BGL package we get a warning like:
```
/home/cgal-testsuite/cgal_doc_build/CGAL-5.4-Ic-33/doc/BGL/PackageDescription.txt:29: warning: ignoring \dot command because HAVE_DOT is not set
```
The BGL package uses the `\dot` and has now to use the setting `HAVE_DOT=YES` to see the dot image.
Till now this went OK as the `\dot` command didn't look at the setting of the `HAVE_DOT` setting in the Doxyfile, though by the issue https://github.com/doxygen/doxygen/issues/7273 and the pull request https://github.com/doxygen/doxygen/pull/8663 it is now required that `HAVE_DOT` is set.
The idea of setting `HAVE_DOT` for the BGL project removed the warning (and shows the figure again) though has also as side effect that the inheritance graphs are shown. Until now CGAL shows for the inheritance just the text version.
Doxygen now has for the `CLASS_GRAPH` setting the possibility `TEXT` that does exactly what is required.
Due to the general setting of `HAVE_DOT` also the not needed `graph_legend` was generated and some `INCLUDE_GRAPH`s, by setting this to `NO ` these are no suppressed as well.
Currently we get a number of warnings when building the documentation for Mesh_3:
```
/home/cgal-testsuite/cgal_doc_build/CGAL-5.3.1-I-169/doc/Mesh_3/Mesh_3.txt:743: warning: unable to resolve reference to 'CGAL/Mesh_3/initialize_triangulation_from_labeled_image.h\' for \ref command
/home/cgal-testsuite/cgal_doc_build/CGAL-5.3.1-I-169/doc/Mesh_3/Mesh_3.txt:801: warning: unable to resolve reference to 'Mesh_3/random_labeled_image.h\' for \ref command
/home/cgal-testsuite/cgal_doc_build/CGAL-5.3.1-I-169/doc/Mesh_3/Mesh_3.txt:817: warning: unable to resolve reference to 'CGAL/Mesh_3/initialize_triangulation_from_gray_image.h\' for \ref command
```
Note the backslash at the end of the file name.
Most likely an attempt was made to escape the dot to not have it as part of the filename, though at least in doxygen 1.8.13 a closing dot was not seen as part of the filename.
Looking at the other escape character of doxygen: the commercial at sign, this was apparently working as escape in the filename as well, though in doxygen 1.8.15 this was not the case anymore either.
During one of the last changes also the backslash lost this possibility for this case and this is now consistent.
The current change (removing the backslashes) doesn't look like to alter the behavior for the 1.8.13 and master version in respect to CGAL.