IBM 6400 Programmer's Reference Manual page 224

Glossary
ascenders separated from descenders and to provide
an aesthetically pleasing interline spacing. The value
of this parameter usually equals the difference
between the vertical font size and the font baseline
extent. Contrast with external leading.
introducer. In GOCA, that part of the data stream
passed from a controlling environment to a
communication processor that indicates whether
entities are to be processed in immediate mode or
store mode. See also immediate mode and store
mode.
IOCA. See Image Object Content Architecture.
IO image. An image object containing IOCA
constructs. Contrast with IM image.
IO-image command set. In the IPDS architecture, a
collection of commands used to present IOCA data in
a page, page segment, or overlay.
IPDS. See Intelligent Printer Data Stream.
K
keyword. A two-part self-defining parameter
consisting of a one-byte identifier and a one-byte
value.
L
landscape. A presentation orientation in which the
X axis is parallel to the long sides of a rectangular
m
physical medium. Contrast with portrait.
language. A set of symbols, conventions, and rules
that is used for conveying information.
See also pragmatics, semantics, and syntax.
LCID. See Local Character Set Identifier.
leading. A printer's term for the amount of space
between lines of a printed page. Leading refers to
the lead slug placed between lines of type in
traditional typesetting. See also internal leading and
external leading.
line attributes. Those attributes that pertain to
straight and curved lines. Examples of line attributes
are line type and line width.
line type. A line attribute that controls the
appearance of a line. Examples of line types are
dashed, dotted, and solid. Contrast with line width.
line width. A line attribute that controls the
appearance of a line. Examples of line width are
normal and thick. Contrast with line type.
208
6400 IPDS
loaded-font command set. In the IPDS architecture, a
collection of commands used to load font information
into a printer and to deactivate font resources.
Local Character Set Identifier (LCID). A local
identifier used as a character, marker, or pattern set
attribute.
local extent. In FD:OCA, the number of subpartitions
within any given partition.
local identifier (LID). An identifier that is mapped by
the environment to a named resource.
location. A site within a data stream. A location is
specified in terms of an offset in the number of
structured fields from the beginning of a data stream,
or in the number of bytes from another location within
the data stream.
logical page. A presentation space. One or more
object areas can be mapped to a logical page. A
logical page has specifiable characteristics, such as
size, shape, orientation, and offset. The shape of a
logical page is the shape of a rectangle. Orientation
and offset are specified relative to a medium
coordinate system.
logical unit. A unit of linear measurement expressed
with a unit base and units per unit-base value. For
example, in MO:DCA and IPDS architectures, the
following logical units are used:
1 logical unit = 1/1440 inch
•
(unit base = 10 inches,
units per unit base = 14400)
1 logical unit = 1/240 inch
•
(unit base = 10 inches,
units per unit base = 2400)
Synonymous with L-unit.
lowercase. Pertaining to small letters as
distinguished from capital letters. Examples of small
letters are a, b, and g. Contrast with uppercase.
L-unit. A unit of linear measurement expressed with
a unit base and units per unit-base value. For
example, in MO:DCA and IPDS architectures, the
following L-units are used:
1 L-unit = l/1440 inch
•
(unit base = 10 inches,
units per unit base = 14400)
1 L-unit = 1/240 inch
•
(unit base = 10 inches,
units per unit base = 2400)
Synonymous with logical unit.