  The far-red portion of the spectrum offers bright prospects for an accurate
classification of cool stars, like the giant components of symbiotic stars. The
8480--8740 Ang region, free from telluric absorptions and where the GAIA
Cornerstone mission by ESA will record spectra for 3x10^8 stars, is
investigated on the base of available observed and synthetic spectral atlases.
We have identified and calibrated diagnostic line ratios useful to derive the
effective temperature (spectral type) and gravity (luminosity class) for cool
stars observed at spectral resolutions 10,000 <= lambda/delta-lambda <= 20,000,
bracketing that eventually chosen for GAIA. A few are presented here.
