SWI-Prolog -- API-function PL_register

Documentation
- Reference manual
  - Foreign Language Interface
    - The Foreign Include File
      - Atoms and functors
        
        Atoms and atom garbage collection
        
        PL_register_atom()
        
        PL_unregister_atom()
- Packages

Availability:C-language interface function

void PL_register_atom(atom_t atom)

Increment the reference count of the atom by one. PL_new_atom() performs this automatically, returning an atom with a reference count of at least one.^{215Otherwise
asynchronous atom garbage collection might destroy the atom before it is
used.}