Here is a list of all related documentation pages:

[Dropped in Code 15] Code 12 Application Metadata
Code Pitfalls - Frequently made mistakes
Environment Variables
Testing for provided features.
Hardware (modalias) dependencies
Code 12 Pattern Packages
Extending ZYpp: Plugins and Hooks
Commit plugin
System plugin
Extended metadata signature checking
Repository metadata verification plugin
Repository Variables
Services
Solver - Vendor protection
Writing and tunning testcases
Libzypp and threads
User data as transaction id
Todo List
Deprecated List