semi合集-English.pdf - 第1559页

SEMI E36-0704  1995, 2004 6 sensitive. (In SGML, names may not be case-sensitive since such na mes may be case-folde d to uppe r case at any time.) Al l element tag names shoul d be in lower case. Entity names and attri…

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SEMI E36-0704 1995, 2004
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module to module, and in fact that is the intent of the
parameter entity framework, all name definitions and
use will be consistent throughout the SEMI E36 DTD
suite. This means that namespace issues, such as those
addressed by the XML Namespace Recommendation
(currently under development), are not relevant within
the scope of SEMI E36. It is likely that mechanisms
such as XML Namespaces will be used to incorporate
parts of the SEMI E36 markup set in other applications;
but this use is outside the scope of SEMI E36 itself.
5.3 Specification for Interchange - Semiconductor
Equipment Manufacturing Information Tagging defines
markup optimized for interchange, not for information
development (authoring) nor for information
presentation (rendering). Thus, some of the capabilities
and functionality that might be desired for authoring or
rendering will not be included in the markup rules, by
design. For example, few elements may be required and
the sequence of elements will not be tightly constrained.
It is anticipated that more specific authoring and
rendering models may be developed by other parties as
part of conforming applications. All conforming
interchange, however, will explicitly follow the markup
and structural rules defined in Semiconductor
Equipment Manufacturing Information Tagging.
5.4 General Modeling Principles
Document (information) models will be
constructed that name the elements, describe the
relationships among these elements, and impose
certain markup or content constraints. The
information markup will be controlled by these
models.
All models will be made available by SEMI and
distributed and balloted as additional parts of
Semiconductor Equipment Manufacturing
Information Tagging. Models will be described in
the second part of Semiconductor Equipment
Manufacturing Information Tagging rather than
included in the base document directly because the
models are assumed to be dynamic documents that
will grow and change as requirements alter. The
data models and the Tag Library may be balloted
separately without requiring a re-balloting of this
part of the specification.
The models will initially be in the form of SGML
and XML Document Type Definitions (DTDs) and
may later include other XML-defining schema.
There will be no all-inclusive general information
models; each DTD or other collection of rules will
model specific elements or specific document
types.
Markup will be primarily designed according to the
nature of the information being described; such
considerations as data volume and ease of
implementation will only be considered
secondarily.
DTDs will be constructed in a modular fashion,
with content-related or structurally-related
modules. The purpose of such modularization is to
reuse existing information content models as much
as possible. New element structures should be
created only when new content is analyzed.
5.5 Information Modeling
5.5.1 Types of Elements - SGML and XML elements
can identify many types of information. There are
situations in which each of the following element types
are appropriate, and many situations in which several
could be used. In designing structures and tagging
documents, elements should be designed using the
following hierarchy of types, from most- to least-
preferred. Only if the information cannot be
satisfactorily identified using one type of element
should those below it in the following list be
considered.
Content Elements — those that identify the
information content, such as Warning, Procedural
Step, Part Number, Installation Manual, or Bill of
Materials.
Structural Elements — those that identify the
structural role of a part of a document, such as
Title, Paragraph, or List Item.
Pointer Elements — those that point to other
locations, either in this document or another, such
as Cross-reference, Footnote Reference, or URL.
Format Elements — those that identify portions of
a document that are to be formatted differently
from surrounding text and for which there is no
Content, Structural, or Pointing reason that they
should be so formatted, for example a Bold
element. Format elements are to be used as a last
resort; use of a content, structure, or pointer
element with a format-related attribute is preferable
to use of a format element.
5.5.2 Naming Elements - Markup in the DTDs will be
named consistently across contexts. That is, the same
element name will be used for an element that can
occur in many places with the same function, regardless
of the location. For example, there is only one element
for Title, not many separate elements for Section Title,
Table Title, Figure Title, etc.
In XML, names are case-sensitive. In the interest of
keeping compliant with XML, all names will be case-
SEMI E36-0704 1995, 2004
6
sensitive. (In SGML, names may not be case-sensitive
since such names may be case-folded to upper case at
any time.) All element tag names should be in lower
case. Entity names and attribute names may be mixed
case, lower case, or upper case to match common usage
of the name involved. If there is no such consideration,
lower case should be used. Attribute values should be
in lower case unless there is a good reason to make
them another case, such as a list of state or country
codes which would naturally appear in upper case.
5.5.3 Recursive Structures - In cases where an element
may contain one or more of the same elements within
itself, there are several styles of modeling the solution:
Use recursive structures. (In recursion, an element
would be allowed to contain itself, thus a <section>
could contain one or more <section>s, which could
themselves contain <section>s, etc.);
Create an explicit hierarchy by naming the top
level and lower levels. (Thus a <section> could
contain one or more <subsections>, which could
themselves contain one or more <sub-subsections>,
etc.); or
Create an explicit hierarchy by numbering the top
level as “1”, and subsequent levels as “2”, “3”, etc.
(Thus a <section1> could contain one or more
<section2>s, which could themselves contain one
or more <section3>s, etc.).
In such cases, recursion should be used to model an
element because it is optimal for authoring, editing, and
data reuse; in such an environment an editor can move a
section from one level to another without needing to
modify the tagging inside the section.
5.5.4 Content Modeling - To create SGML elements
that are maximally re-useable and compatible with
XML, there are several SGML modeling capabilities
that are prohibited in SEMI E36:
RCDATA and CDATA declared content (character
data in which elements and entities cannot be
recognized) are prohibited.
The “AND” connector (which specifies that all the
elements so connected are required but that order is
irrelevant) is prohibited.
Inclusions and Exclusions to content models are
prohibited.
Pernicious mixed element content is prohibited.
This means that if an element model contains
character data it must allow character data at any
place in the model. In practice this means that any
mixed content model groups should be repeatable
“| ” (or) groups.
In addition, the following rules also will apply:
Each element must be declared separately;
No inline comments or empty comments will be
permitted; only full comment declarations may be
used;
The replacement text for external parameter entities
must be well-formed, as per the XML specification
declarations;
The entity types CDATA, PI, and bracketed text
are prohibited;
No Marked Sections are allowed in the DTDs; and
External entities must include both a SYSTEM and
a PUBLIC identifier.
5.5.5 Attributes - The attribute list for each element
must be declared separately. Attribute values must not
contain references to external entities. If a Declared
Value is not a specified list, only the following
Declared Value keywords may be used:
CDATA (character data);
ID (a unique identifier for the element within its
current document);
IDREF and IDREFS (one or more pointer to the
IDs of other elements within the same document);
ENTITY or ENTITIES (the name of one or more
defined entities); and
NMTOKEN or NMTOKENS (one or more words
that consist entirely of name characters).
On all attribute declarations, attribute values specified
as defaults must be literals. Only the following Default
Values keywords may be used:
#REQUIRED (must be present);
#IMPLIED (optional, may be implied by the
application); and
#FIXED (set, not able to be changed).
5.6 Formatting from Element Context versus from
Attributes - The use of formatting attributes to indicate
preferred rendition in display or print should be limited
to situations in which no other mechanism is available.
That is, if the desired formatting can be accomplished
by use of the element name alone, or based on the
context in which the element appears, no formatting
attributes should be used. Elements should only carry
formatting attributes such as “type-size” if there is no
other mechanism to pass this information or if an author
or editor, rather than the output system, must control the
presentation directly. Formatting attributes, when used,
SEMI E36-0704 1995, 2004
7
should be optional and considered advisory by the
rendering agent.
5.7 Data Markup Rules - To create SGML documents
that are maximally re-useable and compatible with
XML, the following restrictions are placed upon the
tagged instances produced in accordance with
Semiconductor Equipment Manufacturing Information
Tagging:
The characters “<” and “&” must always be
escaped as “&lt;” and “&amp;” respectively.
No Marked Sections will be allowed in data
content.
The replacement text of general text entities must
be well-formed, for example, an element that starts
within an entity must also end within it.
All attributes should be present (even default
attributes) and attribute values should be well-
formed, that is with the name, equal sign, and
quotation marks present.
Processing Instructions are prohibited with the
exception of the XML declaration, for example:
<? XML version=˝1.0˝ RMD=' INTERNAL' >.
6 How Semiconductor Equipment
Manufacturing Information Tagging Should Be
Used
6.1 Conformance - A conforming document is one that
meets the markup rules defined for the document class
in Semiconductor Equipment Manufacturing
Information Tagging. A non-conforming document is
one that does not use the markup properly or follow the
markup rules defined in Semiconductor Equipment
Manufacturing Information Tagging. A conforming
document created by an application must be
interchangeable with another conforming application
without significant information loss. A conforming
application may also deliver the markup rules
(information models) for the document or information
class being interchanged to another system.
Conforming applications are those that create, render,
or work with conforming documents. Such applications
may include browsers and online rendering software,
print and composition engines, editors and authoring
systems, search and retrieval engines, etc. In addition
to strictly conforming applications, it is expected that
many applications will accept conforming documents as
input, converting them to the internal format of the
software.
6.1.1 Conforming Authoring Application - A
conforming authoring application must be able to
produce conforming information. An application may
state that it is conformant with Semiconductor
Equipment Manufacturing Information Tagging if it has
the ability to:
Create and manipulate conforming documents;
Create and manipulate one or more classes of
conforming documents;
Import conforming documents into the application
and output matching conforming documents; or
Turn non-conforming documents into conforming
documents.
6.1.2 Conforming Rendering Application - There is no
rendering specification stated or required by
Semiconductor Equipment Manufacturing Information
Tagging at this time. This specification does not define
style conventions or endorse any particular language for
the interchange of stylistic information. That said, a
conforming rendering application is one that can render
(print, display, pronounce, etc.) conforming documents
without significant loss of information. The
presentation should be consistent with the intent of the
originating system, but need not be an exact, facsimile-
reproduction match.
To call itself conforming, a rendering application must
be able to take any conforming document, which is by
definition legal according to this base specification and
the models defined and explained in other parts of the
specification, and render that document in some visual
or non-visual fashion. A conforming rendering
application may not impose additional requirements or
constraints such as content requirements. For example,
a rendering engine may not require the presence of an
element that is optional in the models or require a more
restrictive range of values for an attribute than the
models state.
6.1.3 Validation - Documents tagged according to
Semiconductor Equipment Manufacturing Information
Tagging must parse cleanly according to their SGML or
XML models and must follow the rules stated in this
base document and the Tag Library and other
documentation. Tagging validation must be
accomplished through the use of validating SGML or
XML parsers, in standalone form or as incorporated
into other software packages. (Note: Validation of
some of the rules described in this base document and
the Tag Library documentation cannot be accomplished
using only an XML or SGML parser. This does not
mean that such rules can be ignored, merely that other
validation techniques may be required.) SEMI E36
rules include both rules that can be checked with
software and content rules that can only be verified
intellectually; a conforming SEMI E36 document must
conform to both types of rules.