Introduction to Parameter Entities
This section describes each parameter entity used in the variant Journal Archiving Tag Sets as well as those in the base Suite that are used by this Tag Set, except those that are part of MathML. (Note: The MathML modules come from external sources; see the documentation provided by the authority responsible for the MathML Tag Set. The NISO JATS XHTML-inspired Table Module is maintained and defined as part of NISO JATS, but see also the W3C XHTML documentation. A separate Tag Library describing the OASIS Exchange CALS Table model is available at: http://dtd.nlm.nih.gov/options/OASIS/tag-library/19990315/index.html)
A parameter entity is an XML syntactic construct that allows a name to be given to a collection of elements, attributes, or attribute values so that they can be referred to by name rather than have their members listed every time they are used. For example, the name %person-name.class; stands for all the element components of a person’s name, such as any title or honorific preceding the person’s name, a given (first) name, a surname, and any suffix following the name (such as “Jr.”).
Parameter Entity Pages
Although the parameter entities are declared in many different modules, they are described here in alphabetical order of their XML names (i.e., parameter entity type names). The XML name is the shorter machine-readable name used in XML vocabularies and by software; for example, the XML name %app.class; is used for the parameter entity named Just Appendix Class Elements. Parameter entity names always begin with a percent sign and end with a semi-colon.
Each parameter entity is described by a separate HTML page, where the heading for the page displays the parameter entity’s XML name followed by a more descriptive name. The rest of the parameter entity description page discusses aspects of the parameter entity and its usage. These sections within the page always appear in the following order although any given parameter entity description may not contain all the sections:
This section provides a narrative description of the parameter entity, describing what it contains, what it does, or why and when it should be used.
For some parameter entities, this section provides additional useful information about the parameter entity or its usage.
Design Notes are instructions aimed at implementors, so they may better appreciate the rationale underlying a design decision such as the inclusion of an OR bar within a parameter entity. For example, inline-mix parameter entities always begin with an OR bar to ease customization for those organizations wishing only character data rather than a mixed content model for a particular element.
Contains a copy of the parameter entity’s declaration in XML syntax, i.e., the “content” of the parameter entity. This may contain embedded parameters entities, of the form “%name;”.
Contains a copy of the parameter entity’s declaration in XML syntax, i.e., the “content” of the parameter entity with all embedded parameter entities expanded to their ultimate values.
Parameter Entity Naming Conventions
This Tag Set and the Suite modules have used a series of design and naming conventions consistently. While parsing software cannot enforce these parameter entity usage or naming conventions, these conventions can make it much easier for a person to know how the content models work. The BITS Book Tag Set and the entire JATS DTD Suite use the following usage and naming conventions.
- Classes — Classes are functional OR-groups of
elements. All class names end in the suffix “.class”. For
<!ENTITY % list.class "def-list | list">Classes cannot be made empty; the class should just be removed from all models where you do not want the elements included.
- Mixes — Mixes are OR-groups of classes. All mixes
must be declared after all classes, since mixes are composed of classes. (In best
practice, mixes never contain element names directly.) Mix names have no set suffix,
and only a few have been named “-mix”. Some mixes are
inline to be intermingled with #PCDATA in a mixed content model while
other mixes are grouping of block-level elements. All inline mixes begin with an OR
bar. For example:
<!ENTITY % rendition-plus "| %all-phrase;" >
- Content — Content models and content model
overrides use mixes and classes for all OR groups. Only sequences are made up of
element names directly. Content models overrides are of two types, which are defined
separately to preserve the mixed-content or element-content nature of the models as an
aid to interchange.
- -models — The override of a complete content
model will be named with a suffix “-model”. The
override contains the entire content model, including the
enclosing parentheses, for example:
<!ENTITY % kwd-group-model "(label?, title?, ((%kwd.class; | %x.class;)+ | (%unstructured-kwd-group.class;) )" >
- -elements — A grouping of elements to be
mixed with #PCDATA inside a mixed content model will be named with a
suffix “-elements”. For example, “%kwd-elements;” would be used in the model for
the element <kwd>. All
“-elements” overrides begin with an OR bar, so that a
model may exclude all elements and be reduced to #PCDATA. For
<!ENTITY % kwd-elements "| %all-phrase; | %break.class;" >Could be replaced by
<!ENTITY % kwd-elements "" >
- -models — The override of a complete content model will be named with a suffix “-model”. The override contains the entire content model, including the enclosing parentheses, for example:
- Attribute lists — Attribute lists for a
particular element are named with the name of the element followed by the suffix
“-atts”, so, for example, the attributes for the
<abstract> element would be named
“abstract-atts”. Such lists are not reused as frequently
as they might be in many tag sets, to provide maximum flexibility. Attribute lists for
different elements were rarely tied together. The parameter entities contain at least
one complete line of an attribute list, excluding the ATTLIST
<!ENTITY % sec-atts "%jats-common-atts; #IMPLIED xml:lang NMTOKEN #IMPLIED sec-type CDATA #IMPLIED disp-level CDATA #IMPLIED specific-use CDATA #IMPLIED" >