On classical instruments like violin and cello a chord notated with three or more simultaneous notes is assumed to be bowed starting on the lowest string to the highest.
However, at times chords should be bowed in the opposite direction – starting on the highest string and bowing towards the lowest. Is there any standard notation to indicate this variant?
For arpeggiated chords there is a common notation: a standard low-to-high arpeggio is shown on the first chord here, while the arpeggio notation to play high-to-low gets an arrow at the bottom, as in the second chord:
Unfortunately, whether the line adjacent to a chord is straight or wavy, in classical notation it is assumed to be an arpeggio, not a chord. So my first inclination to use a straight vertical line with a down arrow would not be interpreted correctly.