In APIs, which of the following is NOT a common serialization format?

The correct answer is based on the understanding of serialization formats commonly used in APIs for data interchange. XML (Extensible Markup Language), JSON (JavaScript Object Notation), and YAML (YAML Ain't Markup Language) are all widely accepted formats for serializing data. They are designed to represent data structures in a way that is easy for machines to parse and generate, making them suitable for API communication, where data needs to be transferred over the network.

HTML (HyperText Markup Language), on the other hand, is primarily a markup language used for structuring content on the web, specifically for creating web pages and applications. While HTML can include data, its main purpose is to lay out and present that data in a browser, rather than to serve as a serialization format for APIs. APIs require formats that efficiently encode and decode data, such as XML, JSON, and YAML, which focus on data representation rather than web page rendering. Thus, HTML does not fit within the context of common serialization formats used for APIs.