Quantum Scalar 1000 Operator's Manual page 241

All labels are restricted to lengths of 5 to 16 characters in
extended mode, and 6 characters plus a media identifier in the
default and media ID modes. In default mode, the media
identifier is ignored by the library firmware. In media ID
mode, the media identifier is required.
The seventh or eighth character media identifier may be
separate from the barcode label, as in the case of ½-inch media,
or may be embedded in the barcode label, as in the case of
SDLT/DLT media.
The AIT barcode labels do not provide media identifier
characters but contain an embedded checksum character,
which will be disregarded by the library firmware in default
and media ID modes. In extended mode, the checksums and
media identifiers are reported as part of the barcode label.
Understanding Barcodes 6-17
22 June 2004