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DDML
Document Definition Markup Language (DDML) is an XML schema language proposed in 1999 by various contributors from the xml-dev electronic mailing list. It was published only as a W3C Note, not a Recommendation, and never found favor with developers. DDML began as XSchema, a reformulation of XML DTDs as full XML documents, so that elements and attributes, rather than declarations, could be used to describe a schema. As development continued, the name was changed to DDML, reflecting a shift away from the goal of replicating all DTD functionality, in order to concentrate on providing a robust framework for describing basic element/attribute hierarchy. DDML offered no datatypes or functionality beyond what DTDs already provided, so there was not much advantage to using DDML instead of DTDs. DDML did, however, inform the development of the next generation of XML-based schema languages, including the more successful XML Schema and RELAX NG In computing, RELAX NG (REgular LAnguage f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XML Schema
An XML schema is a description of a type of Extensible Markup Language, XML document, typically expressed in terms of constraints on the structure and content of documents of that type, above and beyond the basic syntactical constraints imposed by XML itself. These constraints are generally expressed using some combination of grammatical rules governing the order of elements, Boolean predicates that the content must satisfy, data types governing the content of elements and attributes, and more specialized rules such as uniqueness quantification, uniqueness and referential integrity constraints. There are languages developed specifically to express XML schemas. The document type definition (DTD) language, which is native to the XML specification, is a schema language that is of relatively limited capability, but that also has other uses in XML aside from the expression of schemas. Two more expressive XML schema languages in widespread use are XML Schema (W3C), XML Schema (with a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XML Schema (W3C)
XSD (XML Schema Definition), a recommendation of the World Wide Web Consortium (W3C), specifies how to formally describe the elements in an Extensible Markup Language (XML) document. It can be used by programmers to verify each piece of item content in a document, to assure it adheres to the description of the element it is placed in. Like all XML schema languages, XSD can be used to express a set of rules to which an XML document must conform to be considered "valid" according to that schema. However, unlike most other schema languages, XSD was also designed with the intent that determination of a document's validity would produce a collection of information adhering to specific data types. Such a post-validation ''infoset'' can be useful in the development of XML document processing software. History XML Schema, published as a W3C recommendation in May 2001, is one of several XML schema languages. It was the first separate schema language for XML to achieve Recommendation stat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Mailing List
A mailing list is a collection of names and addresses used by an individual or an organization to send material to multiple recipients. The term is often extended to include the people subscribed to such a list, so the group of subscribers is referred to as "the mailing list", or simply "the list." Transmission may be paper-based or electronic. Each has its strength, although a 2022 article claimed that "direct mail still brings in the lion’s share of revenue for most organizations." Types At least two types of mailing lists can be defined: * an ''announcement list'' is closer to the original sense, where a "mailing list" of people was used as a recipient for newsletters, periodicals or advertising. Traditionally this was done through the postal system, but with the rise of email, the electronic mailing list became popular. This type of list is used primarily as a one-way conduit of information and may only be "posted to" by selected people. This may also be referred to by t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Document Type Definition
A document type definition (DTD) is a set of ''markup declarations'' that define a ''document type'' for an SGML-family markup language ( GML, SGML, XML, HTML). A DTD defines the valid building blocks of an XML document. It defines the document structure with a list of validated elements and attributes. A DTD can be declared inline inside an XML document, or as an external reference. XML uses a subset of SGML DTD. , newer XML namespace-aware schema languages (such as W3C XML Schema and ISO RELAX NG) have largely superseded DTDs. A namespace-aware version of DTDs is being developed as Part 9 of ISO DSDL. DTDs persist in applications that need special publishing characters, such as the XML and HTML Character Entity References, which derive from larger sets defined as part of the ISO SGML standard effort. Associating DTDs with documents A DTD is associated with an XML or SGML document by means of a document type declaration (DOCTYPE). The DOCTYPE appears in the syntactic f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Datatype
In computer science and computer programming, a data type (or simply type) is a set of possible values and a set of allowed operations on it. A data type tells the compiler or interpreter how the programmer intends to use the data. Most programming languages support basic data types of integer numbers (of varying sizes), floating-point numbers (which approximate real numbers), characters and Booleans. A data type constrains the possible values that an expression, such as a variable or a function, might take. This data type defines the operations that can be done on the data, the meaning of the data, and the way values of that type can be stored. Concept A data type is a collection or grouping of data values. Such a grouping may be defined for many reasons: similarity, convenience, or to focus the attention. It is frequently a matter of good organization that aids the understanding of complex definitions. Almost all programming languages explicitly include the notion of data ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RELAX NG
In computing, RELAX NG (REgular LAnguage for XML Next Generation) is a schema language for XML—a RELAX NG schema specifies a pattern for the structure and content of an XML document. A RELAX NG schema is itself an XML document but RELAX NG also offers a popular compact, non-XML syntax. Compared to other XML schema languages RELAX NG is considered relatively simple. It was defined by a committee specification of the OASIS RELAX NG technical committee in 2001 and 2002, based on Murata Makoto's RELAX and James Clark's TREX, and also by part two of the international standard ISO/IEC 19757: Document Schema Definition Languages ( DSDL). ISO/IEC 19757-2 was developed by ISO/IEC JTC 1/SC 34 and published in its first version in 2003. Schema examples Suppose we want to define an extremely simple XML markup scheme for a book: a book is defined as a sequence of one or more pages; each page contains text only. A sample XML document instance might be: This is page one. This is pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XML Markup Languages
Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing arbitrary data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. The World Wide Web Consortium's XML 1.0 Specification of 1998 and several other related specifications—all of them free open standards—define XML. The design goals of XML emphasize simplicity, generality, and usability across the Internet. It is a textual data format with strong support via Unicode for different human languages. Although the design of XML focuses on documents, the language is widely used for the representation of arbitrary data structures such as those used in web services. Several schema systems exist to aid in the definition of XML-based languages, while programmers have developed many application programming interfaces (APIs) to aid the processing of XML data. Overview The main purpose of XML is serialization, i. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
