how to create properties (with value sliders) for in the 3dview properties panel - Basics & Interface - Blender Artists Community
Batch add custom properties - Python API - Developer Forum
Read custom properties defined in Blender from scene loaded from GLTF - General Discussion - jMonkeyEngine Hub
I figured out how to use custom properties in shaders and the compositor (Shader AOV). Here's a quick cheat-sheet to get you started. : r/blenderTutorials
Custom Properties, Drivers and Intermediate Shape Keys - BlenderNation
Create custom properties for an object and write them to a text file - Python Support - Blender Artists Community
Batch add custom properties - Python API - Developer Forum
Custom properties and drivers in blender made easy - YouTube
Custom Properties panel should have more options, and show on the N-menu - User Feedback - Developer Forum
Blender - how to make a slider custom property (from custom property panel) - Python Support - Blender Artists Community