In the docs, Emulating plucked instruments: Plectrum Tracks, section Patterns, at the end:
However, do note that you must specify either one or all the strings if you are not using a range. Again, you cannot do:
1. 0 80 90 ‘‘Wrong!!
This is confusing, since the example preceding it reads "1.0 0 90" and one could easiliy interpret this as 1.0 80 90 (which, in fact, is valid).
So it would better be written as
1.
0 0 80 90