$v \sin i$ is the parameterised amount of rotational broadening that is required to match the spectrum being considered. $v$ is the equatorial velocity of a star and $i$ is the (generally unknown) angle between the line of sight and the spin-axis of the star.
When you have a binary system then it is possible that either one or both of the stars contributes significantly to the spectrum. These are labelled as SB1 or SB2 systems respectively.
Most binary systems are SB1s. That is because even a small mass difference between the components leads to a large luminosity difference. In these cases, the $v \sin i$ value is the projected equatorial velocity of the luminous component.
In the case of an SB2 then it is quite possible that the $v\sin i$ value is meaningless, or at least requires careful interpretation, because the lines of both stars are present in the spectrum and may be displaced in velocity with respect to each other.
@Heoyou should see an autocomplete function with their ID and you can just select it.(screenshot of example) For more see How do comment @replies work? (found in FAQ) $\endgroup$