new in 5.3

Since release 5.3, Audiveris can handle tremolos as depicted below:

A tremolo is composed of 1, 2 or 3 slanted segments.

It must be horizontally aligned with a chord, either a stem-based chord or a stem-less chord. Both cases are shown in picture above.

Audiveris does not yet address the case of tremolos located between two chords, as shown in the picture below, stolen from Wikipedia:

If the OMR engine has not recognized a tremolo, you can always assign or drag the desired tremolo from the shape palette, using the BeamsEtc shape set.

Tremolo editing is limited to translations of the item, which will snap on compatible chords nearby.