Sequential writes.
.TP
.B trim
-Sequential trims (Linux block devices only).
+Sequential trims (Linux block devices and SCSI character devices only).
.TP
.B randread
Random reads.
Random writes.
.TP
.B randtrim
-Random trims (Linux block devices only).
+Random trims (Linux block devices and SCSI character devices only).
.TP
.B rw,readwrite
Sequential mixed reads and writes.
ioctl, or if the target is an sg character device we use
\fBread\fR\|(2) and \fBwrite\fR\|(2) for asynchronous
I/O. Requires \fBfilename\fR option to specify either block or
-character devices. The sg engine includes engine specific options.
+character devices. This engine supports trim operations. The
+sg engine includes engine specific options.
.TP
.B null
Doesn't transfer any data, just pretends to. This is mainly used to