1. Whole lines 2. keywords in the current file 3. keywords in 'dictionary' 4. keywords in 'thesaurus', thesaurus-style 5. keywords in the current and included files 6. tags 7. file names 8. definitions or macros 9. Vim command-line 10. User defined completion 11. omni completion 12. Spelling suggestions 13. keywords in 'complete'