The choice of the unique magnitude used for the determination of the
target observing time with Hipparcos depends on the shape of the
luminosity curve of each type of variable star. It can be the magnitude
at minimum or maximum luminosity, a mean, or a weighted magnitude
(Mennessier & Figueras 1989). This information is given for stars with
a variability code of 3 or 4 (as specified by the first digit of field
26), whenever the necessary information on the luminosity curve was
available. It is coded as given in Table V4 
.
