Hello! Thank you very much for your answer. The trick worked for me too,
and is remarkably hassle-free.
My "solution":
\markright{short}
\section{looooooooooooooooooooooooooooooooooong title}
\markright{short}
The only thing is that the section number does not appear in the header
that way. So, assuming it was section A, I had to put in the following:
\markright{A. SHORT TITLE}
\section{looooooooooooooooooooooooooooooooooong title}
\sectionmark{short title}
The long title will appear in the TOC.
It does, no problem there.
But i think that this will cause
problems when the section starts on a new page...
I have not noticed that.
I haven't tried it with chapters; maybe there is a problem that the
short title appears on the page before the new chapter (because this
always uses a new page)!?
Actually, the same problem cannot happen with chapters, since the first
page of the chapter has no header. Then, from the second page onward, all
is fine, it follows whatever \chaptermark you decided to give it.
Cheers,
Catherine
