The notes are referred by means of the Rns number, e.g. the running
number in Renson et al. (1991)'s General Catalogue of Ap
and Am Stars.
Most of the notes are reported to indicate the binarity character of
some stars.
Visual doubles are indicated if the companion star is closer than about
30 arcsec and the magnitude difference 
is smaller than 5 or 6
magnitudes. This because our aim is to evidentiate the possibility that the
presence of a companion might jeopardize the measurements. The informations
we give generally concern the ADS number (Aitken 1932), if
available, the angular distance in arcsec, and the magnitude difference
between the components.
The spectroscopic binary character is indicated if the period is
known; these data are mainly from Batten et al. (1978)
catalogue.
Some notes are introduced to point out errors found in the literature
or to put in evidence some very interesting characteristic.
Acknowledgements
We would like to thank all colleagues who have supplied their results making easier the hard task of updating the catalogue.