"My guess it that this is to model OOP-based systems:" No, SGML which became XML is a separate independent track from OOP. They both set themselves up in some

"My guess it that this is to model OOP-based systems:" No, SGML which became XML is a separate independent track from OOP. They both set themselves up in some concrete before they really encountered each other and the contact was a mess. This is part of why the DOM, especially the first couple of iterations, are so messy (reading DOM 1 is almost hilarious in hindsight, if you know what you're reading for [1])... it doesn't help that the DOM also smashed into yet another tech line, the dynamically-typed scripting language, face first. The hasty three-way committee-arranged shotgun marriage in the late 1990s between these techs produced a fairly dysfunctional family. [1]: https://www.w3.org/TR/REC-DOM-Level-1/level-one-core.html https://www.w3.org/TR/REC-DOM-Level-1/level-one-core.html Notice this API, primarily used by Javascript, is specified in Java, complete with specifications of checked exceptions. Total clusterfuck. And a prime example of just how hard Java was inorganically jammed down the programming community's throats (which I say without regard to your current opinion of the language, it did grow up certainly, but the initial push was completely inorganic); this standard is 1998, with Java 1.0 release 1996. Java 1.2 (or 2.0 depending on how you look at it) was released in 1998, with such notable features as... the first Collections support in the library. This was not a language mature enough to be writing specifications in yet, even ignoring that you shouldn't be writing specifications like this in a specific language anyhow, especially since it was obvious and known it was going to be cross-language anyhow.