This example defines a reusable LaTeX environment for creating formatted text boxes, or “encadrés,” within a thesis document. It uses the `tcolorbox` package to draw a framed box with a white background and a black border, and integrates with the `cleveref` package through `\crefformat` and `\Crefformat` to generate cross-references. The code shows how to customize the box’s appearance, such as removing rounded corners and setting title styling, and includes commented usage instructions for creating labeled boxes and citing them in the text. The source is a gist by RCura.