[Orgmode] Hook Function Examples

[Mark Elston]

I am trying to make use of some of the hooks for exporting and haven't
found any docs about what they take or how to make use of them (elisp
is *not* my native language).

In particular, I am trying to figure out how to use the following
to see if any of them are going to help me:

 org-export-preprocess-hook
 org-export-preprocess-after-tree-selection-hook
 org-export-preprocess-final-hook

Any examples of a hook function for these would help a lot.  In
particular, what are the parameters, is the point "looking at"
anything in particular, etc.

Mark