[u]

1. u_char
2. u_long
3. u_short
4. uid_t
5. umode_t
6. un_wp_page
7. unblank_screen
8. unexpected_floppy_interrupt
9. unexpected_hd_interrupt
10. unlock_buffer
11. unlock_inode
12. unmap_page_range
13. unsignify
14. update_screen
15. usage
16. ushort
17. ustat
18. utimbuf
19. utsname