Sections

  1. Executable programs or shell commands
  2. System calls (functions provided by the kernel)
  3. Library calls (functions within program libraries)
  4. Special files (usually found in /dev)
  5. File formats and conventions, e.g. /etc/passwd
  6. Games
  7. Miscellaneous (including macro packages and conventions), e.g. man(7), groff(7), man-pages(7)
  8. System administration commands (usually only for root)
  9. Kernel routines (Non standard)

To see if any COMMAND has available sections use whatis of man -f

man -f COMMAND