1 INTRODUCTION

2 FOLLOW-UP SPECTROSCOPY

3 SPECTRAL ANALYSIS
3.1 Model atmospheres
3.2 Spectral fitting with XTGRID
3.3 Binary spectral decomposition
3.4 Spectral fitting

4 PROPERTIES OF HOT SUBDWARFS
4.1 The Teff-log g plane
4.2 The Teff-He diagram
4.3 CNO trends
4.4 Binaries

5 LUMINOSITY AND MASS DISTRIBUTION

6 MODELLING HOMOGENEITY

7 SUBDWARF POPULATIONS

8 CATALOGUE OF SUBLUMINOUS STARS

9 CONCLUSIONS