> 
>> In the document (manuscript of a book) that I am working, ALT_TITLE now works in most cases. However, ALT_TITLE does not work for headlines in Appendices, which come after 
>> 
>> \begin{appendices} 
> 
> Are you sure the problem isn't on the LaTeX side?  Where does the
> appendices environment come from?  It appears not to be defined in
> LaTeX2e nor in the standard classes.
> 

I am sorry, it has nothing to do with appendices. Although I am not able to exactly figure out where the problem is, I have an example file where ALT_TITLE gets exported only for one headline and not for the others. Please see the attached org and and latex files.

Vikas