GitLab CI only:

https://docs.gitlab.com/ee/ci/yaml/#only--except

Official example

job1:
  script: echo
  only:
    - main
    - /^issue-.*$/
    - merge_requests

job2:
  script: echo
  except:
    - main
    - /^stable-branch.*$/
    - schedules

Both are equivalent (official example):

job1:
 script: echo
 only:
   - branches

job2:
 script: echo
 only:
   refs:
     - branches

except:

See also

• gitlab-ci.yml[ job: | stage: | stages: | artifacts: | include: | script: | when: | only: | needs: | extends: ]
• GitLab CI, variables, templates, executors, .gitlab-ci.yml, .gitlab/, Credential helpers, notifications, pipeline editor, Keyword reference, Changelog, ContainersNotReady, GitLab environments, CI_JOB_TOKEN, artifacts: