Xmodmap

! xmodmap accepts the following input expressions:
! 
!     pointer = default              reset pointer buttons to default
!     pointer = NUMBER ...           set pointer button codes
!     keycode NUMBER = [KEYSYM ...]  map keycode to given keysyms
!     keysym KEYSYM = [KEYSYM ...]   look up keysym and do a keycode operation
!     clear MODIFIER                 remove all keys for this modifier
!     add MODIFIER = KEYSYM ...      add the keysyms to the modifier
!     remove MODIFIER = KEYSYM ...   remove the keysyms from the modifier
! 
! where NUMBER is a decimal, octal, or hex constant; KEYSYM is a valid
! Key Symbol name; and MODIFIER is one of the eight modifier names:  Shift,
! Lock, Control, Mod1, Mod2, Mod3, Mod4, or Mod5.  Lines beginning with
! an exclamation mark (!) are taken as comments.  Case is significant except
! for MODIFIER names.
! 
! Keysyms on the left hand side of the = sign are looked up before any changes
! are made; keysyms on the right are looked up after all of those on the left
! have been resolved.  This makes it possible to swap modifier keys.

!Standard KeySym names are obtained from <X11/keysymdef.h> by removing the XK_ prefix from each name: XK_cent -> cent

! XStringToKeysym() and XKeysymToString() functions will also handle
! any keysym string of the form "U0020" to "U007E" and "U00A0" to   
! "U10FFFF" for all possible Unicode characters. In other words,   
! every possible Unicode character has already a keysym string      
! defined algorithmically, even if it is not listed here keysymdef.h

! xmodmap -pke
! xmodmap -pk

!keycode  14 = 5 percent 5 percent permille leftdoublequotemark
!                        5 Shift+5 Alt-Gr+5 Alt-Gr+Shift+5
!                        5 %       ‰        “

!YEN
!keycode  26 = e E e E EuroSign
!keycode  26 = e E e E EuroSign yen currency
keysym e = e E e E EuroSign yen

! U+2665 BLACK HEART SUIT
!keycode  49 = section onehalf grave asciitilde dead_stroke
keysym section = section onehalf grave asciitilde U2665

! U+2642 MALE SIGN
! U+2640 FEMALE SIGN
!keycode  24 = q Q q Q q Q
!keycode  24 = q Q NoSymbol NoSymbol malesymbol femalesymbol

! U+221E INFINITY
!keycode  17 = 8 parenleft 8 asterisk bracketleft less
keysym 8 = 8 parenleft 8 asterisk bracketleft infinity

! U+2260 NOT EQUAL TO
!keycode  19 = 0 equal 0 parenright braceright degree
!keysym 0 = 0 equal 0 parenright braceright degree
keysym 0 = 0 equal 0 parenright braceright notequal

! U+00AC NOT SIGN
!keycode 103 = End NoSymbol End
!keysym End = End notsign