This document presents IoT-Lite, a lightweight semantic model for annotating data in the Internet of Things. IoT-Lite aims to address issues of heterogeneity and interoperability in IoT systems by providing a simple way to semantically describe sensors, actuators, and other devices. It reuses existing models like SSN and defines best practices for annotation. Evaluations show IoT-Lite imposes minimal overhead on data size and query time compared to other semantic models. The goal of IoT-Lite is to make semantic descriptions transparent and easy to implement for both end users and data producers.