register_library
Core (amxmodx.inc)
Description
register_library - Registers your plugin as a library.
Syntax
register_library ( const name[] )
Type
Native
Notes
You can put #pragma library <name in your include files, and plugins that use your include without loading your plugin will get a nice error message.

This native technically just makes the Core think your plugin is a module; this is part of the "auto-module" system where failed plugins automatically know what modules they need.