The main body of the Geneva data is formed by a systematic observations of open clusters closer than 500 pc and of a few other selected clusters. Some stars have a rather high weight because they have been observed more intensively to study their variability, like Be and Ap stars.
See the comprehensive description of the photometric system by
M. Golay (1973, Vistas in Astronomy 14, 13 and 1980, Vistas in Astronomy
24, 141) for more explanations.
|[U-B]||:||[U-B] colour index|
|[B-V]||:||[B-V] colour index|
|U-B1||:||U-B1 colour index|
|B2-V1||:||B2-V1 colour index|