Results of my experiments with growisofs v7.1.
First column shows intended action: first four for direct writing of
files, last two for writing image. First row shows current format of
disc. Body of table shows growisofs options required to get intended
result.

                         DVD-RW Seq.        DVD-RW Res.

start appendable         -Z                 -Z

create single            -dvd-compat -Z      n/a (1)

continue appendable      -M                 -M

write final              -dvd-compat -M      n/a (2)

write image (first       -Z                 -Z
session, appendable)

write image (first       -dvd-compat -Z      n/a (1)
session, non-appen.)


1. not available: using "-dvd-compat -Z" doesn't create non-appendable disc
2. not available: using "-dvd-compat -M" doesn't close disc

