Introduction to Standard Universal Markup Language

The "Universal Slogan" is an international standard for information management published by the International Organization for Standardization in 1986 (ISO 8879: 1986 Information Processing). An identical standard of ISO/ANSI/ECMA, a specification for annotating text documents and providing type information about document fragments. This standard defines formatting, indexing, and linking information for text documents that are platform- and application-independent, providing users with a syntax-like mechanism for defining the structure of a document and tags that indicate the structure of the document. The meaning of "mark" refers to the mark inserted into the document.

Marks are divided into two types: one is called "programmatic markup", which is used to describe the style of document display; the other is called "descriptive markup", which is used to describe the text in the document. purpose. The basic idea behind developing a "universal tagline" is to separate the content of a document from its style.

The pioneer and foundation of "Universal Markup" is the "IBM Universal Markup Language", which is today's strategic collection of rules for creating structured document description languages. Many web pages are represented by hypertext markup, which is an example of using the concepts of "IBM Universal Markup Language" to create documents. Extensible Markup Language is also rooted in "IBM Universal Markup Language".

In addition to the standard set of "Universal Standards", it will eventually include: "Universal Standards" file exchange format, document style semantics and specification language, standard page description language, text description and processing language A reference model, a standard for the exchange of font and character information, and a set of standard fonts. Advantages: High stability. The ISO 8879 "Universal Slogan" is an international standard specification, so its credibility is quite high, and its normative structure is also quite rigorous. In addition, the "Universal Slogan" has been used for more than 20 years, and has been in use since 1996. The specifications of "Universal Markup" have almost never changed, so "Universal Markup" is a fairly mature universal markup language. Highly portable "universal tag" files can be used across platforms, such as on different computer hardware or operating systems, or even by different application software, because the "universal tag" is a highly portable It is a stable international standard and has been used for more than 20 years. Therefore, there are many application software and related data conversion technologies that support its format. Therefore, the "Universal Slogan" files can be widely used in various application fields. Of course, other Portability can be relatively improved. High Integrity considered the need to satisfy a wide range of users when formulating the "Universal Suggestions", so its specifications are quite complete and can meet the needs of users in different application fields, and families used in conjunction with the "Universal Suggestions" such as HyTime The document style semantics and specification language are also international standards. For example, HyTime complies with the ISO/IEC 10744 standard. Its main function is a language for describing dynamic files, while the document style semantics and specification language comply with the ISO/IEC 10179 standard. There are two goals in formulating it. One is to formulate a sample form for displaying a "universal slogan" document, and the other is to have the function of converting languages. Documents can be used more rationally, resulting in an improved life cycle; publishing costs are reduced; information can be easily reused, generating a value added to the document (eg: printing, hypertext databases). 2. Disadvantages

The "universal slogans" mentioned above have the advantages of high stability and completeness, which can make the "universal slogans" applicable to various application fields, but this The opposite is also the fatal shortcoming of the "universal slogan". High complexity. Due to the high integrity and stability of the "Universal Slogan", its complexity is also relatively high. This can be said to be the main flaw of the "Universal Slogan". If it is formulated using the "Universal Slogan" grammar specification It may take several years to fully understand the standards for the elements, attributes, and content entities in the DTD. It can be seen that the entire "universal tag" system is too complete and becomes complicated.

Not only is the "Universal Slogan" itself complicated, but also the development of software related to the "Universal Slogan" has become complicated. In terms of developing a "Universal Slogan" parser, it is used to check the "Universal Slogan" "The control tags and formats in the file would take tens of thousands of lines to write using C (a set of "object-oriented high-level programming languages" developed using more basic programming languages). Expensive. From the high complexity of "Universal Standards", it is relatively derived from high costs. As mentioned before, "Universal Standards" are usually applied by large enterprises to a large amount of data. When "Universal Standards" are applied The file format definition DTD must be formulated before so that users can follow the file structure defined in this DTD. However, the file data used in it is usually complex, so it will take a long time to formulate the DTD, so the development can The cost of applying DTD is quite expensive.

Secondly, due to the independence of "universal slogans", universal slogans are useful in many situations. Compared with the extensible markup language, the definition function is very powerful. The disadvantage is that the universal markup is not suitable for World Wide Web data description, and the "universal markup" software is very expensive. There are opinions suggesting how comments should be formatted in "universal taglines" rather than as a language.

So the following design was proposed: Unified quotation of Baidu Encyclopedia entries = Standard Universal Markup Language; Markup structure Baidu Encyclopedia/ Entries = Standard Universal Markup Language;

Baidu Encyclopedia (entries = Standard Universal Markup Language)