addseverity (3)      - introduce new severity classes
bootparam (7)        - Introduction to boot time parameters of the Linux kernel
initramfs-tools (8)  - an introduction to writing scripts for mkinitramfs
intro (1)            - Introduction to user commands
intro (2)            - Introduction to system calls
intro (3)            - Introduction to library functions
intro (4)            - Introduction to special files
intro (5)            - Introduction to file formats
intro (6)            - Introduction to games
intro (7)            - Introduction to overview, conventions, and miscellany section
intro (8)            - Introduction to administration and privileged commands
LDP (7)              - Intro to the Linux Documentation Project, with help, guides and documents
perlcompile (1)      - Introduction to the Perl Compiler-Translator
perlguts (1)         - Introduction to the Perl API
perlintro (1)        - - a brief introduction and overview of Perl
perluniintro (1)     - Perl Unicode introduction
twintro (8)          - introduction to Tripwire software