[U]

1. UADD
2. UADDOV
3. UCS2UTF_NBYTES
4. ULTRIX
5. UMAX
6. UMUL
7. UMULOV
8. UNALIGNED
9. UNCOLLECTABLE
10. UNCOLLECTABLE_CDR
11. UNCOLLECTABLE_DEBUG_BYTES
12. UNDO
13. UNIQUE_THRESHOLD
14. UNIX_ADDRESS_PATH_MAX
15. UNIX_LIKE
16. UNLOCK
17. UNMAP_THRESHOLD
18. UNPROTECT
19. UNSET_LOCK_HOLDER
20. UP
21. UPPER_MASK
22. USED_HEAP_SIZE
23. USE_ASM_PUSH_REGS
24. USE_COMPILER_TLS
25. USE_GC
26. USE_GENERIC_PUSH_REGS
27. USE_HDR_CACHE
28. USE_MARK_BYTES
29. USE_MMAP
30. USE_MMAP_ANON
31. USE_PROC_FOR_LIBRARIES
32. USE_PTHREAD_LOCKS
33. USE_PTHREAD_SPECIFIC
34. USE_SPIN_LOCK
35. USE_STD_ALLOCATOR
36. USE_TEMPORARY_MEMORY
37. USUB
38. USUBOV
39. UTF8_SUBST
40. UTF8_SUBST2_CHAR1
41. UTF8_SUBST2_CHAR2
42. UTF8_SUBST2_CHAR3
43. UTS4
44. Undisguise