[4] Fowler was born and grew up in Walsall, England, where he went to Queen Mary's Grammar School for his secondary education.

DSLs are said to be defined by being composable programming languages, with their focus on an individual domain and having limited expressiveness.

[10]: 27  It is argued that DSLs can increase productivity by removing the requirement of the programmer to understand a full programming language, providing a means of communication with domain experts, and separate the manner of execution of a task from the definition of a task itself.

[10]: 14  Various examples of DSLs are presented including graphviz, a language for specifying graphs to be rendered; JMock, a java mocking framework; CSS, a language to specify stylistic elements of a website; HQL, an object relational mapper in Java; XAML, a language used to specify and change graphical user interfaces; FIT, a language to express testing scenarios; and make, a tool to build software[10]: 147 The book discusses implementing an external DSL using tools like parsers, lexers, abstract syntax trees and code generation referred to as "syntax-driven translation"[10]: 219  This is contrasted with "delimiter-driven translation" which is said to be simpler but less powerful.

Here the language is simple enough to be interpreted by splitting on delimiters and switching logic based on individual entries.