Yet at the same time, it proves to require quite a bit of refinement when we look at the incredibly broad spectrum of different markup languages, and markup language applications, that are now proliferating. At the Extreme 2000 conference on markup technologies here in Montreal, Allen Renear picked up the task of scrutinizing the opposition, proposing an alternative framework for which he introduced terms from linguistics and speech-act theory. Apart from its format, to what do we refer to determine what “content” is; how do we specify it, and how do we go about designing tags for it? The traditional arguments around the “descriptive/procedural” distinction have detailed a number of advantages to descriptive markup languages (also loosely identified as “generic” languages) over their procedural cousins: scalability, reusability of data, and so forth.Maxwell (1981) outlined three separate domains for encoding music notation in a computer: .This model was later extended by the Standard Music Description Language (SMDL), an encoding system that was expressed using the Standard General Markup Language (SGML) (SGML was a precursor to XML.) SMDL built upon the Maxwell’s model and extended it to define a representation model consisting of four domains for music notation representation: domain includes the musical content or structure including pitches, time values, articulations, dynamics, and all other elements—defined as the symbols that communicate the composer’s intentions.The validators determine whether a document actually follows the rules for the language(s) it uses.A document that passes this process with success is called valid.
To help facilitate this process, the W3C makes available a number of validation tools which analyze the coding of a webpage against a particular standard.
XML - Ideal for Highly Structured Information If you're familiar with HTML, you'll recognize XML - which is short for "e Xtensible Markup Language".
When combined with an XML Schema Definition (XSD), which defines how an XML document must be structured, the data exchanged between two systems can be validated for consistency and completion on the fly, offloading that responsibility from the code that will process that data.
Why are we still talking about the “descriptive/procedural” distinction? While these advantages are demonstrably real, nonetheless the evolution of XML technologies, especially in such applications of XML as XSLFO, SVG, SMIL, or even XSLT, shows that the opposite approach to designing a markup language also is playing an important role.
The conception continues to be a focus, because it continues to have explanatory power. Sometimes, it is clear, a procedural language is exactly what we want.