Description
Names
Description
Subject Indicators
http://www.techquila.com/psi/general/Description
Topics of type Description
Occurrences of type Description
Used to indicate that some field of the schema
contains a key value. A key value must be unique and may
not be nillable.
in topic key
List datatypes are those having values each of
which consists of a finite-length (possibly empty)
sequence of values of an atomic datatype.
in topic List Datatype
Indicates that the content model of an element
contains only character data and no elements. Using this
element it is possible to create an element definition
which has a simple type as the content and one or more attributes.
in topic simpleContent
An attribute use plays a role similar to that
of a particle, but for attribute declarations: an
attribute declaration within a complex type definition
is embedded within an attribute use, which specifies
whether the declaration requires or merely allows its
attribute, and whether it has a default or fixed value.
in topic Attribute Use
A model group definition is an association
between a name and a model group, enabling re-use of the
same model group in several complex type definitions.
in topic Model Group
This element may be used to group (and
optionally name) part of a content model. If named, then
the group may be subsequently reused in other content models.
in topic group
Indicates whether or not locally declared
elements must be qualified by the target namespace in an
instance document. If the value of this attribute is
'unqualified', then locally declared elements
should not be qualified by the target namespace. If the
value of this attribute is 'qualified', then
locally declared elements must be qualified by the
target namespace.
in topic elementFormDefault
Used to provide fixed values for both
attribute and element instances. When a fixed value is
specified for an attribute declaration, then any
instance of that attribute that appears in the instance
document must have the specified value and if the
attribute does not appear, it will be provided by the
schema processor with that attribute value. When a fixed
value is specifeid for an element declaration, then any
occurrence of that element in the instance document must
either be empty or have content which matches the value
of the fixed attribute, and any empty elements will have
the value of the fixed attribute provided as its content
by the schema processor.
in topic fixed
Constrains the value of a simple type to a
maximum length.
in topic maxLength
If the value of this attribute is
'true' on an element declaration, then the
content of an instance of this element may be flagged as
being null in an instance by the xsi:nil attribute on
the instance element.
in topic nillable
Indicates that the content model of an element
contains only other elements.
in topic complexContent
A grouping element which allows only one of
its children to appear in an instance.
in topic choice
Constrains the value of a simple type to a
minimum value.
in topic minInclusive
Used to provide information regarding the
schema to other applications.
in topic appInfo
Defines the element for which this element may
be used interchangeably.
in topic substitutionGroup
Provides a schema-wide default value for the
'block' attribute.
in topic blockDefault
A topic definition from the normative text of
a W3C Technical Recommendation.
in topic Normative Definition
A constraint which requires that the element
information items match the particles in sequential order.
in topic Conjunction
A model group is a constraint in the form of a
grammar fragment that applies to lists of element
information items. It consists of a list of particles,
i.e. element declarations, wildcards and model groups.
in topic Model Group Definition
Constrains the value of a simple type to a
minimum length.
in topic minLength
A constraining facet is an optional property
that can be applied to a datatype to constrain its value space.
in topic Constraining Facet
Used to indicate that a particular value in a
schema instance must be a reference to a key defined
elsewhere in that instance. This element uses an XPath
selector and field elements to indicate the key
references in the instance.
in topic keyref
A mention of the subject in the XML Schema Primer.
in topic Primer Mention
A particle used in a complex type definition
to constrain the validation of the [children] of an
element information item.
in topic Content Model
A type definition whose declarations or facets
are in a one-to-one relation with those of another
specified type definition, with each in turn restricting
the possibilities of the one it corresponds to, is said
to be a restriction. The specific restrictions might
include narrowed ranges or reduced alternatives. Members
of a type, A, whose definition is a restriction of the
definition of another type, B, are always members of
type B as well.
in topic Restriction
Used in simple type declarations to identify
the additional constraints to be applied on the derived
type. Used in complex type declarations to indicate that
the derived type is a more restrictive form of the base type.
in topic Restriction
Determines the maximum number of times that an
element may appear in a content model. The value of this
attribute may be a positive integer value or the term
'unbounded' to indicate that there is no
maximum number of occurrences.
in topic maxOccurs
A complex type definition which allows element
or attribute content in addition to that allowed by
another specified type definition is said to be an extension.
in topic Extension
Defines the default value for both attributes
and elements. When specified for an attribute
definition, the value of the 'default'
attribute will be the value provided by the schema
processor if the element in the instance document does
not provide a value for the attribute itself. When
specified for an element, the value of the
'default' attribute will be assigned as the
element content if the element exists in the instance
document and the element in the instance document is empty.
in topic default
Provides a schema-wide default value for the
'final' attribute.
in topic finalDefault
Allows a type to be created directly at the
point at which it would normally be referenced in a
content model. This enables element/attribute types
which are used just once to be created without the
overhead of creating and naming a separate type and then
referencing it from the content model.
in topic Anonymous Type Definitions
A grouping element which requires that each of
its children appear in the order in which they are declared.
in topic sequence
Constraints on the schema components
themselves, i.e. conditions components must satisfy to
be components at all.
in topic Schema Component Constraint
Global elements are created as children of the
schema element. Once created, a global element may be
referenced in one or more content models using the ref attribute.
in topic Global Elements
Schema component is the generic term for the
building blocks that comprise the abstract data model of
the schema.
in topic Schema Component
A container for elements providing
documentation regarding a schema construct.
in topic annotation
Determines the minimum number of times that an
element is required to appear in a content model. If the
value of this attribute is 0, then the element is optional.
in topic minOccurs
Augmentations to post-schema-validation
infosets expressed by schema components, which follow as
a consequence of validation and/or assessment.
in topic Schema Information Set Contribution
Indicates how XML from other namespaces
(introduced by the any element in a content model)
should be validated. The value for this attribute may be
one of 'strict' (the processor must retrieve
the schema declaration associated with the namespace and
validate the XML); 'lax' (the processor should
attempt to validate the XML against its schema); and
'skip' (the processor should not attempt to
validate the XML).
in topic processContents
Used to introduce definitions and declarations
from another namespace into a schema.
in topic import
Elements containing no content (neither
character data nor elements)
in topic Empty Elements
Declaration components are associated by
(qualified) name to information items being validated.
in topic Declaration Component
Indicates whether or not the declared
element/attribute must be qualified by the target
namespace in an instance document. If the value of this
attribute is 'unqualified', then the
element/attribute should not be qualified by the target
namespace. If the value of this attribute is
'qualified', then the element/attribute must
be qualified by the target namespace.
in topic form
Contributions to validation associated with
schema components.
in topic Schema Validation Constraint
A constraint which requires that the element
information items match the particles in sequential order.
in topic Sequence
The core XTM concept of class; the role of
class as played by one of the members of a
class-instance association.
in topic XTM Class
Used to extend the content model of an
existing complex type. When deriving a new complex type
by extension, the content model of the derived type is
considered to be a sequence consisting of the content
model of the base type followed by the content model of
the extension. An extension type will be valid in any
content model where its base type is valid, however the
xsi:type attribute must be used in the instance to
indicate the extension type being used.
in topic extension
Specifies the namespace for the vocabulary
defined by the schema.
in topic targetNamespace
A value space, and hence a datatype, is said
to be ordered if there exists an order-relation defined
for that value space.
in topic Ordered Datatype
A facet is a single defining aspect of a value
space. Generally speaking, each facet characterizes a
value space along independent axes or dimensions.
in topic Facet
An element declaration is an association of a
name with a type definition, either simple or complex,
an (optional) default value and a (possibly empty) set
of identity-constraint definitions. The association is
either global or scoped to a containing complex type definition.
in topic Element Declaration
A particle is a term in the grammar for
element content, consisting of either an element
declaration, a wildcard or a model group, together with
occurrence constraints. Particles contribute to
validation as part of complex type definition
validation, when they allow anywhere from zero to many
element information items or sequences thereof,
depending on their contents and occurrence constraints.
in topic Particle
Constraints the value of a simple type to a
maximum value.
in topic maxInclusive
A datatype is bounded if its value space has
either an inclusive upper bound or an exclusive upper
bound and either an inclusive lower bound and an
exclusive lower bound.
in topic Bounded Datatype
Determines whether an attribute is required to
appear on an element. Unlike elements, attributes may
appear only once or not at all. The value of this
attribute must be one of 'required' (the
attribute must have a value specified),
'optional' (the attribute may have a value
specified) or 'prohibited' (the attribute must
not have a value specified).
in topic use
An attribute group definition is an
association between a name and a set of attribute
declarations, enabling re-use of the same set in several
complex type definitions.
in topic Attribute Group Definition
This element allows a set of attribute
declarations to be grouped together and named so that
they may then be reused in multiple content models
throughout the schema.
in topic attributeGroup
The core XTM concept of instance; the role of
instance as played by one of the members of a
class-instance association.
in topic XTM Instance
Indicates whether or not locally declared
attributes should be qualified in the instance. If the
value of this attribute is 'unqualified', then
locally declared attributes are not qualified by the
target namespace. If the value of this attribute is
'qualified', then locally declared attributes
must be qualified by the target namespace.
in topic attributeFormDefault
Used in a simple type declaration to make the
type into a list of atomic elements.
in topic list
Used to bring in definitions and declarations
contained in another file. The included definitions and
declarations must be in the target namespace of the
including schema.
in topic include
Indicates a content model that allows any
element to appear. The content may be restricted to a
specific namespace (or set of namespaces) by providing a
value for the namespace attribute (a white-space
separated list of namespace URIs). Special values for
the namespace attribute can also be used to indicate
that the content may be from any namespace other than
the one being defined or that the content should be
unqualified XML.
in topic any
Constraints on the representation of schema
components in XML beyond those which are expressed in
Schema for Schemas.
in topic Schema Representation Constraint
Used to define a uniqueness constraint on a
type. The uniqueness constraint may apply to a single
field or collection of fields relative to a selection of
elements in the instance document. The selection of the
elements and the fields to be unique are made using
XPath expressions.
in topic unique
The core XTM concept of class-instance; the
class of association that represents class-instance
relationships between topics.
in topic XTM Class-Instance Association
Includes all the declarations and definitions
from another schema file, and allows some or all of
those declarations and definitions from that file to be
replaced by new definitions.
in topic redefine
An annotation is information for human and/or
mechanical consumers. The interpretation of such
information is not defined in this specification.
in topic Annotation
Union datatypes are those whose value spaces
and lexical spaces are the union of the value spaces and
lexical spaces of one or more other datatypes.
in topic Union Datatype
Indicates that this element/attribute cannot
be used in an instance document. The instance document
must instead use a element/attribute of a derived type
(using the xsi:type attribute to indicate the derived
type used).
in topic abstract
Used to constrain the value of a simple type
to one of a set of predefined tokens.
in topic enumeration
A fundamental facet is an abstract property
which serves to semantically characterize the values in
a value space.
in topic Fundamental Facet
If the value of this attribute is
'true', then the element content may contain
both character data and elements.
in topic mixed
Used to prevent derivation from this type.
Values may be 'restriction' (prevents
derivation by restriction), 'extension'
(prevents derivation by extension) or '#all'
(prevents any derivation from this type).
in topic final
Indicates that any attribute from the
namespace specified in the namespace attribute is
allowed to appear as an attribute.
in topic anyAttribute
Provides hints to a schema processor about
where to find the schema for one or more namespaces.
Values are provided as a white-space separate list of
URIs. URIs must appear in pairs - first the namespace
URI, then the location of the schema document for that namespace.
in topic schemaLocation
A grouping element which indicates that each
of its children may occur either once or not at all and
that the children may occur in any order. This element
must be the top level of any content model.
in topic all
There is a complex type definition nearly
equivalent to the ur-type definition present in every
schema by definition. The ur-type allows any content of
any kind (both text and elements).
in topic Ur-Type
Used to prevent the replacement of this type
in an instance document with an instance of certain
derived types. The value of this attribute can be one of
'restriction' (prevents a type derived by
restriction being used in place of this type),
'extension' (prevents a type derived by
extension being used) or '#all' (prevents any
derived type being used).
in topic block
An identity-constraint definition is an
association between a name and one of several varieties
of identity-constraint related to uniqueness and
reference. All the varieties use XPath expressions to
pick out sets of information items relative to
particular target element information items which are
unique, or a key, or a ·valid· reference, within a
specified scope. An element information item is only
·valid· with respect to an element declaration with
identity-constraint definitions if those definitions are
all satisfied for all the descendants of that element
information item which they pick out.
in topic Identity Constraint Definition
Used to provide human-readable documentation
of a schema construct.
in topic documentation
Indicates the type of the element in the
instance document. This attribute should be present when
an instance of a derived type is used in an document at
a point where its base type was declared in the content
model in the schema.
in topic type
There is a simple type definition nearly
equivalent to the simple version of the ur-type
definition present in every schema by definition.
in topic anySimpleType
A constraint which requires that the element
information items match one of the particles.
in topic Disjunction
An attribute added to an instance of a
nillable element to explicitly indicate a
"null" value for the element content.
in topic nil
Constrains the content of simple type to match
a regular expression.
in topic pattern