ISO/IEC ISP 11186-1:1996
(Main)Information technology — International Standardized Profiles FVT3nn — Virtual Terminal Basic Class — Register of attribute assignment type definitions — Part 1: FVT321 — Font Assignment Type No. 1
Information technology — International Standardized Profiles FVT3nn — Virtual Terminal Basic Class — Register of attribute assignment type definitions — Part 1: FVT321 — Font Assignment Type No. 1
Contains the definition of a font assignment type that enables a font assignment value to be specified as a font resource property-list in accordance with ISO/IEC 9541-1.
Technologies de l'information — Profils normalisés internationaux FVT3nn — Classe de base du terminal virtuel — Registre de définitions de type d'allocation d'attribut — Partie 1: FVT321 — Type d'allocation font no 1
General Information
Relations
Standards Content (Sample)
INTERNATIONAL ISO/IEC
STANDARDIZED ISP
11186-I
PROFILE
First edition
1996-09-01
Information technology - International
Standardized Profiles FVT3nn - Virtual
Terminal Basic Class - Register of attribute
assignment type definitions -
Part 1:
FVr32 1 - Font Assignment Type No. 1
Technologies de /‘information - Profils normalis& internationaux FVT3nn
- Classe de base du terminal virtue/ - Registre de definitions de type
d ’allocation d ’attribut -
Partie I: FVr32 I - Type d ‘alloca tion font no 1
Reference number
lSO/IEC ISP II 186-I :I 996(E)
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ISO/IEC ISP 11186-1: 1996(E)
Contents Page
Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
iv
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 Scope . 1
1.1 General . 1
1.2 Position within the taxonomy . 1
1.3 Scenario . 2
3
2 Normative references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.............................................. 3
3 Definitions.
3.1 General 0% terminology . 3
3.2 Terminology of VT base standards . 3
3.3 Terminology of font information interchange standards . 4
3.4 Terminology of coded character set standards . 4
4 Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
5 Principles of conformance to VT Profiles . . . . . . . . . . . . . . . . . . . , . . . . 4
6 Entrynumber. 4
7 Name of sponsoring authority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
8 Date . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
9 Identifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . l . . . . . . . . . . . . 4
10 Descriptor value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -. . , 5
5
11 Font designation .
11.1 Underlying principles . 5
6
11.2 Font description properties .
12 Writing mode specification . 8
12.1 Glyph coordinate system . 8
12.2 Modal properties . 8
13 Relationship between font and emphasis . . . . . . . . . s . . . . . . . . . , . , . 9
14 Abstract syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . ,
9
0 ISO/IEC 1996
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ii
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43 ISO/IEC
ISO/IEC ISP 11186-l : 1996(E)
Foreword
IS0 (the International Organization for Standardization) and IEC (the International
Electrotechnical Commission) form the specialized system for worldwide
standardization. National bodies that are members of IS0 or IEC participate in the
development of International Standards through technical committees established by
the respective organization to deal with particular fields of technical activity. IS0 and
IEC technical committees collaborate in fields of mutual interest. Other international
organizations, governmental and non-governmental, in liaison with IS0 and IEC, also
take part in the work.
In the field of information technology, IS0 and IEC have established a joint technical
committee, lSO/lEC JTC 1. In addition to developing International Standards, lSO/lEC
JTC 1 has created a Special Group on Functional Standardization for the elaboration
of International Standardized Profiles.
An International Standardized Profile is an internationally agreed, harmonized document
which identifies a standard or group of standards, together with options and
parameters, necessary to accomplish a function or set of functions.
Draft International Standardized Profiles are circulated to national bodies for voting.
Publication as an International Standardized Profile requires approval by at least 75%
of the national bodies casting a vote.
International Standardized Profile lSO/lEC ISP 11186-l was prepared with the
collaboration of
- OSI Asia-Oceania Workshop (AOW);
- European Workshop for Open Systems (EWOS);
- Open Systems Environment Implementors’ Workshop (OIW).
ISO/IEC ISP 11186 consists of the following parts, under the general title information
technology - Internatr ’onal Standardized Profiles M3nn - Virtual Terminal Basic
C/ass - Register of attribute assignment type definitions:
- Part I: M32I - Font Assignment Type No. I
- Fart 2: M3II - Repertoire Assignment Type for lSO/lEC 10646
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0 ISO/IEC
ISO/IEC ISP 11186-l : 1996(E)
Introduction
ISO/IEC ISP 11186 is defined within the context of Functional Standardization, in
accordance with the principles specified in ISO/IEC TR 10000, “Framework and
Taxonomy of International Standardized Profiles ”. The context of Functional
Standardization is one part of the overall field of Information Technology (IT)
standardization activities, covering base standards, profiles and registration
mechanisms.
The Open Systems Interconnection (OSI) Standard IS0 9040 for the Virtual Terminal
Basic Class Service provides for the identification of attribute assignment types by
means of ASN.1 object identifiers. This International Standardized Profile provides a
means for the registration of such attribute assignment type definitions in accordance
with ISO/IEC 9834-l. The individual entries in this register constitute Interchange
Format and Representation Profiles (F-Profiles) within the framework of lSO/lEC
TR 10000.
This part of ISO/IEC ISP 11186 was developed in close cooperation between the three
Regional OSI Workshops, namely the OSE Implementors’ Workshop (OIW) of the
United States, the European Workshop for Open Systems (EWOS) and the OSI Asia-
Oceania Workshop (AOW). It was developed under the editorship of EWOS from an
attribute assignment type definition contained in the European pre-standard
ENV 41 513. The text is harmonized between these three Workshops and it has been
ratified by the plenary assemblies of each Workshop.
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lSO/IEC ISP 111864 : 1996(E)
INTERNATIONAL STANDARDIZED PROFILE @ ‘So ”EC
International Standardized
Information technology -
Profiles FVT3nn - Virtual Terminal Basic Class - Register
of attribute assignment type definitions -
Part 1:
- Font Assignment Type No.1
FvT321
The three International Registers of VT information objects
1 Scope
and the specifications of VT Application Profiles are each
1 .l General published as a separate multi-part ISP as follows:
The concept of Profiles for OSI, and the structure of the - lSO/lEC ISP 11184 is the Register of VTE-profiles;
International Standardized Profiles that document them, are
defined in ISO/IEC TR 10000-l. Such Profiles are divided into - lSO/IEC ISP 11185 is the Register of control object
a number of different classes and sub-classes. Two of these type definitions;
classes contain sub-classes comprising functions of the
- ISO/IEC ISP 11186 is the Register of attribute
Virtual Terminal Basic Class Service and Protocol specified
in the base standards ISO 9040 and IS0 9041. These are the assignment type definitions;
Application Profiles (A-Profiles) and the Interchange Format
- ISO/IEC ISP 11187 contains the specifications of VT
and Representation Profiles (F-Profiles).
Application Profiles,
The relationship between A-Profiles and F-Profiles is
This part of ISO/IEC ISP 11186 contains the definition of a
described in 7.3.2 of lSO/IEC TR 10000-l and is as follows.
Application Layer base standards require, implicitly or font assignment type that enables a font assignment value to
be specified as a font resource property-list in accordance
explicitly, the structure of information carried or referenced by
with lSO/lEC 9541-I. The properties that may be included in
them to be specified for each instance of communication. It
the property-list are specified as a subset of the properties
is the purpose of F-Profiles to specify such information
structures. Particular functional requirements may then be defined for a character cell font. Particular provision is made
for font resources in which the height and width of a
met by the combination of an A-Profile with one or more F-
Profiles. character cell are integer multiples of the height and width of
the character boxes that comprise the graphical images
Establishment of a VT-association involves the selection by considered by the VT service. Provision is also made for the
negotiation of a particular Virtual Terminal Environment profile use of both left-to-right and right-to-left writing modes and for
(VTE-profile), and of particular values for any arguments of the coexistence of both modes in the display object.
that VTE-profile. The VTE-profile specification, and possibly
also the values of certain VTE-profile arguments, may in turn 1.2 Position within the taxonomy
reference the definitions of VT control object types and
attribute assignment types. These VTE-profiles, control object The taxonomy of International Standardized Profiles for OSI
types and attribute assignment types are therefore Information is laid down in lSO/IEC TR 10000-2. Within the classification
Objects that require explicit reference within the VT protocol. scheme of this taxonomy, the OSI Profiles specified in this
International Standardized Profile are in the Virtual Terminal
Particular instances of these Information Objects are fully
defined within the base standards, but the base standards Registered Object sub-class of the class of Interchange
Format and Representation Profiles.
also provide for further instances to be defined by
registration. Each registered instance constitutes an F-Profile
within the framework of lSO/IEC TR 10000. A Profile within this subclass has a Profile identifier of the
form FVT&c, where abc is a structured numerical identifier
that identifies the position of the Profile within each of the
The Virtual Terminal Basic Class Service and Protocol may
be used to realise a wide range of distinct functions. three levels of subdivision of the subclass. The values of a
Particular functions may be realised through the selection of and b are single digits but c is an integer that is not
appropriate VT functional units, F-Profiles and other VTE- necessarily a single digit.
profile argument values. The specification of the selection
required to realise a particular function and to promote In principle the IS0 Virtual Terminal model allows for multiple
interoperability constitutes a Virtual Terminal A-Profile within classes of operation, although at the time of publication of
the framework of ISO/IEC TR 10000. this International Standardized Profile only the Basic Class
1
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0 ISO/IEC
ISO/IEC ISP 111864 : 1996(E)
font attribute is subservient to the character-repertoire attribute
has been defined. The value of the identifier component a
in that a separate set of permitted values for the font attribute
distinguishes between distinct types of information object as
is specified for each permitted value of the character-
follows:
repertoire attribute. The values permitted for the other
secondary attributes are mutually independent.
-a=
1 for Basic Class VTE-profiles;
With the exception of the emphasis attribute, an attribute
-a=
2 for Basic Class Control Objects;
assignment is composed of two parts, a type and a value.
For the emphasis attribute, the syntax of permitted values is
-a=
3 for Basic Class Assignment Types.
prescribed by the VT service base standard IS0 9040 and the
semantics of each value is determined by the specification of
Values of a greater than 3 are reserved for future
the VTE-profile currently in use. For all other secondary
developments.
attributes, the assignment type determines both the syntax of
the permitted values and the semantic interpretation of each
This International Standardized Profile lSO/lEC ISP 11186
such value.
contains the specifications of the Profiles with identifiers of
the form FVT3bc. For this form of identifier, the component
b distinguishes between the three attributes of display object
array elements for which assignment types are defined in
accordance with IS0 9040. The values of b are allocated as
follows:
-b=
1 for repertoire assignment types;
VT service-provider
- -
Conceptual Communkation Area
- b = 2 for font assignment types;
CDS] / DSD
- b = 3 for colour assignment types,
,-, I/ FRepAT-ll pigq . . . /RepAT-n
The identifier component c is the serial number of the
Dos piei-j IFonlAT-pj . . . piKq
attribute assignment type in the sub-register for the particular
attribute concerned. Values of b greater than 3 are reserved
/ piq . . . jColAT-nI
Oil
for further attributes that may be defined as subject to
registration in future amendments to IS0 9040.
This part of lSO/lEC ISP 11186 contains the definition of the
font assignment type with the Profile identifier Figure 1 - Attribute assignment types in
the VT Service model
FVT321 - Font Assignment Type No.1.
Assignment type definitions are required for only three distinct
1.3 Scenario
attributes, namely repertoire, font and colour, since both
foreground-colour and background-colour secondary
The specification of the Virtual Terminal Service is given in
attributes reference the same assignment types. The attribute
IS0 9040. It is based on a model in which two VT-users
assignments specified by the parameter values of a VTE, and
communicate by means of a shared Conceptual the assignment type definitions to which they refer, are held
in the Data Structure Definition (DSD) component of the CCA.
Communication Area (CCA) that is a conceptual part of the
VT service-provider. Information exchange is modelled by This is illustrated in figure 1, in which RepAT-1, RepAT-2, .,.
RepAT-n represent a number of different repertoire
one VT-user updating the content of the CCA and the
assignment types, FontAT-I, FontAT-2, . . . FontAT-n represent
changed state of the CCA then being made accessible to the
a number of different font assignment types and ColAT-1,
peer VT-user.
ColAT-2, . , .
ColAT-n represent a number of different colour
assignment types. The negotiation during establishment of
The CCA is structured by the Virtual Terminal Service into a
a VT-association will determine whether or not these will
number of components. Of these components, the
include the attribute assignment type whose definition is given
Conceptual Data Store (CDS) contains one or two display
in this part of ISO/IEC ISP 11186.
objects (DOS), each of which includes a one, two or three
dimensional array of array elements. Each array element is
NOTE - A VTE-profile specification may prescribe the attribute
either empty or has a content that consists of a primary
assignments that are present in any VTE established by its use, or
attribute and a number of secondary attributes. The primary
may provide VTE-profile arguments for the negotiation of these
attribute value selects one character-box graphic element
attribute assignments, or may use a combination of these methods.
Where some or all of the attribute assignments are determined by
from a repertoire of such elements that is determined by the
negotiation, attribute assignment types are referenced by their
character-repertoire secondary attribute. The other secondary
registered name. The permitted syntax of the corresponding
attributes are the font, emphasis, foreground-colour and
attribute assignment value is determined by the definition that has
background-colour attributes which are collectively referred to
this registered name. Since the VT service-provider is not required
as rendition attributes.
to have knowledge of these registered definitions, in principle
the VT-users provide the VT service-provider with such
The values permitted for the secondary attributes are
information through local management procedures. Whether or not
specified by attribute assignments that are included among this is necessary in practice depends on the nature of the
the parameters of a Virtual Terminal Environment (VTE). The implementations concerned.
2
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0 ISO/IEC
lSO/IEC ISP 111864 : 1996(E)
3.1 General OSI terminology
2 Normative references
3.1.1 This part of ISOJIEC ISP 11186 makes use of the
The following documents contain provisions which, through
following terms defined in ISO/IEC 10731:
reference in this text, constitute provisions of this part of
ISOAEC ISP 11186. At the time of publication, the editions
a) service primitive;
indicated were valid. All documents are subject to revision,
and parties to agreements based on this part of
b) service-provider.
ISOAEC ISP 11186 are warned against automatically
applying any more recent editions of the documents listed
3.1.2 This part of ISO/IEC ISP 11186 makes use of the
below, since the nature of references made by ISPs to such
following terms defined in ISO/IEC 8824:
documents is that they may be specific to a particular
edition. Members of IEC and IS0 maintain registers of
a) any type;
currently valid International Standards and ISPs, and CCITT
maintains published editions of its current Recommendations.
b) component type;
lSO/lEC 6429: 1992, lnformation technology - Control
functions for coded character sets (third edition).
c) information object;
ISO/IEC 7498-l : 1994, Information technology - Open
d) module;
Systems Interconnection - Basic Reference Mode/: The
Basic Model. (See also ITU-T Recommendation X.200).
e) object descriptor type;
ISO/IEC 8824-l : 1995, information technology - Abstract
9 object identifier;
Syntax Notation One (ASN.1): Specification of basic notation
(third edition), (See also ITU-T Recommendation X.680).
g) parent type (of a subtype);
IS0 9040:1990, information technology - Open Systems
h) structured type;
Interconnection - Wtual Terminal Basic C/ass Service.
i) subtype (of a parent type).
IS0 9041-I: 1990, Information technology - Open Systems
Interconnection - Virtual Terminai Basic Class Protocol -
3.1.3 This part of lSO/IEC ISP 11186 makes use of the
Part I: Specification.
following terms defined in lSO/IEC 9834-l:
ISO/IEC 9541-I : 1991, Information technology - Font
a) registration;
information interchange - Part I: Architecture.
b) registration-hierarchical-name.
ISO/lEC 9541-2: 1991, Information technology - Font
information interchange - Part 2: interchange format.
3.2 Terminology of VT base standards
ISO/IEC 9834-l : 1993, Information technology - Open
3.2.1 This part of ISO/IEC ISP 11186 makes use of the
Systems Interconnection - Procedures for the operation of
following terms defined in IS0 9040:
OSI Registration Authorities - Part I: Genera/ procedures.
(See also CCITT Recommendation X.660).
a) array element;
ISO/IEC TR 10000-1: 1995, information technology -
b) character-box graphic element;
Framework and taxonomy of International Standardized
Profiles - Part I: General principles and documentation
c) character-repertoire;
framework (third edition).
d) display object;
ISO/IEC TR 10000-2: 1995, Information technology -
Framework and taxonomy of International Standardized
e) primary attribute;
Profiles - Part 2: Principles and Taxonomy for OS1 profiles
(fourth edition).
9 rendition attributes;
ISO/IEC 10646-I : 1993, Information technology - Universal
g) secondary attribute;
Multiple-Octet Coded Character Set (UCS) - Part I:
Architecture and Basic Multilingual Plane.
h) VT-association;
lSO/lEC 10731: 1994, lnformation technology - Open
i) W-environment (VTE);
Systems Interconnection - Basic Reference Model -
Conventions for the definition of OS1 services. (See also
j) VT-user;
ITU-T Recommendation X.21 0).
k) VTE-parameter;
3 Definitions
I) W-E-profile;
For the purposes of this part of lSO/lEC ISP 11186, the
following definitions apply. m) VI-E-profile argument.
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0 ISO/IEC
ISO/IEC ISP 11186-l : 1996(E)
3.3 Terminology of font information interchange by VTE-profile specifications given in FVTlnn Profiles, by
standards control object type definitions given in FVT ’Lnn Profiles and
by VT Application Profiles given in AVTnn Profiles.
3.3.1 This part of ISO/lEC ISP 11186 makes use of the
following terms defined in ISO/IEC 9541-l : There is no concept of conformance to an FVT3nn Profile in
isolation. An FVTlnn Profile that references an FVT3nn
a) escapement;
Profile may place requirements on an implementation of the
VT protocol to be able to negotiate the presence in the CCA
b) font;
of attribute assignments of the type concerned. An FVTtin
Profile may impose similar requirements concerning FVT3ln
c) font reference;
Profiles if it permits negotiation of values for the CO-
repertoire-assignment VTE-parameter.
d) font resource;
NOTE an
- The use of attribute assignment type by a VTE-profile
e) glyph;
specification will have no effect on the operation of the VT protocol
unless the attribute assignment concerned is subject to negotation
9 glyph coordinate system;
during association establishment. Attribute assignments are
referenced in display object update operations by their position in an
9) glyph image;
ordered list, so that the PDUs carrying these operations are
transparent to the specific assignments being referenced.
h) posture;
Such requirements of FVTlnn and FVT2nn Profiles reference
i) presentation surface;
the syntax of attribute assignment values as specified by the
attribute assignment type concerned. A system that includes
j> pwefiy;
an implementation of the VT protocol may be claimed to
conform also to an AVTnn Profile. Conformance to an AVTnn
k) property-list;
Profile may require that the image of the display object array
I) proportionate width; presented by a real display device is in accordance with
semantics specified by the attribute assignment type
m) structured-name; definitions referenced by the contents of the array elements.
Conformance to attribute assignment type semantics is not
n) weight;
within the scope of conformance to any FVTnnn Profile.
o) writing mode.
In accordance with these conformance principles, an FVT3nn
Profile does not provide a Profile Requirements List as
3.4 Terminology of coded character set standards
defined by lSO/lEC 9646-l.
3.4.1 This part of ISO/IEC ISP 11186 makes use of the
following terms defined in lSO/lEC 10646-l :
6 Entry number
a) cell;
The remaining clauses of this part of lSO/IEC ISP 11186
provide the entry for the Font Assignment Type No.1 in the
b) character;
International Register of VT Attribute Assignment Type
Definitions. This register complies with the requirements of
c) coded character;
lSO/IEC 9834-l concerning registration authorities that
operate in a technical role. This International Register is
d) coded character set.
maintained as three sub-registers, one each for repertoire,
font and colour assignment-type definitions.
4 Abbreviations
This entry is the first in the sub-register for font assignment
type definitions. This register assigns it the entry number:
For the purposes of this part of ISO/IEC ISP 11186, the
following abbreviations apply.
FONT-l.
ASN.1 Abstract Syntax Notation One
CCA Conceptual Communication Area
7 Name of sponsoring authority
CDS Conceptual Data Store
DO Display Object
This entry is sponsored by the European Workshop for Open
DSD Data Structure Definition
Systems (EWOS).
PDU Protocol Data Unit
vl- Virtual Terminal
VTE Virtual Terminal Environment
8 Date
All other abbreviations used are defined in lSO/lEC
The date of submission of this proposal was 1994-09-14.
TR 10000-l.
5 Principles of conformance to VT Profiles 9 Identifier
Profiles with taxonomy identifiers of the form FVT3nn provide The name assigned to an information object by an
attribute assignment type definitions for reference as required
International Register is required by ISO/IEC 9834-l to be a
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0 ISO/IEC
ISO/IEC ISP 11186-I : 1996(E)
registration-hierarchical-name. A registration-hierarchical-
- glyph complement;
name may have more than one form. The permitted forms
include an ASN.1 object identifier as defined in lSO/lEC 8824
- nominal writing mode.
and a distinguished name as defined in ISO/IEC 9594-2.
The first five of these properties concern the font design, in
In accordance with annex A of ISO/IEC 9834-1, this register
that they affect the individual glyphs of a font resource. The
assigns the following object identifier form for the name of glyph complement specifies the set of all glyphs that are
this register entry: included in at least one writing mode that is defined for the
font resource. A writing mode specifies those properties of
{ iso standard(O) 11186 1 font(3) fontl(1) }.
a font resource that affect the positioning of the glyph images
relative to one another. The nominal writing mode of a font
In accordance with 18.3 of IS0 9040, this object identifier
resource is the writing mode that is to be used if no other
shall be used as the font-assignment-type component of a
writing mode is specified in a font reference. With the
value of the font-assignment VTE-parameter to specify this
exception of the glyph complement, which is determined by
register entry as providing the method used to designate the
the value of the character-repertoire rather than the font
font and to determine the form of the font-assignment-value
secondary attribute of an array element, the values of these
component.
properties are specified as parameters within a font
assignment value of this font assignment type.
This register does not assig n any other form to the name of
this entry.
The properties listed above are all classified in ISO/IEC
9541-1 as font description properties. Writing modes are
NOTE - By ISO/IEC 9834-l a distinguished name for the purposes
themselves specified by a further list of properties known as
of the OSI Directory may only be assigned together with an object
modal properties. Each writing mode available for a
identifier when the object identifier form is generated under the arc
particular font is identified within lSO/lEC 9541-1 by a
( joint-isoccitt(2) country(l6) country-name }.
structured-name. The names available for the nominal writing
mode property within this assignment type are specified in
11.2.7. The values of the modal properties for each named
10 Descriptor value
mode are specified in 12.2.
The value of the ASN.l object descriptor type assigned to
There are further lSO/lEC 9541-1 properties that are neither
this register entry is:
listed above nor determined in accordance with 12.2 by the
writing mode concerned. These properties either describe
“FVT321: Font Assignment Type No. 1 ‘I.
aspects of a font resource that are treated by IS0 9040 as
controlled by the emphasis secondary attribute (e.g. scores)
or are beyond the resolution of terminals to which this
11 Font designation
assignment type is appropriate (e.g. posture angle).
11 .l Underlying principles
11.1.2 Character cell model
11 .I .I Font references
The character-box model of graphic elements used in VT
models glyphs as rectangular boxes which are all of the
The font designation scheme of this assignment type uses
same width and height and which may be imaged
the font reference data structure specified in annex A of
consecutively to form text strings and text lines. This
ISO/IEC 9541-2. A font reference is intended for use in the
corresponds to a character cell font as described in 8.7.1.3
identification and selection of a font resource that matches
of ISO/IEC 9541-1. This assignment type allows the
the set of property values specified in the font reference.
simultaneous use of more than one character cell font without
ISO/IEC 9541-2 states that the font reference data structure
requiring all such fonts to use the same size of character cell.
which it defines may be used directly as a font reference (by
specifying the selection semantics), or may be used as a
The relative sizes of the character cells of different fonts are
building block for more complex font selection or substitution
specified in terms of the standard character-box of the VT
requirements. It also states that only those properties
model. This standard character-box is the box that is used
considered to be relevant to the originator need be specified
to determine the values of the device-minimum-x-array-length
in a font reference. This assignment type takes the former
and device-minimum-y-array-length VTE-parameters. Within
course, using the font reference data structure of lSO/lEC
this assignment type, individual fonts may have character
9541-2 by specifying the relevant properties and
...
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