I would like to be able to more easily compose the skull and
crossbones (☠), up and down arrows (↑,↓), and an umbrella (☂).
So i propose the following additions to
/usr/share/X11/locale/en_US.UTF-8/Compose :
<Multi_key> <O> <X> : "☠" U2620 # SKULL AND CROSSBONES
<Multi_key> <asciicircum> <bar> : "↑" U2191 # ARROW UP
<Multi_key> <bar> <asciicircum> : "↑" U2191 # ARROW UP
<Multi_key> <bar> <v> : "↓" U2193 # ARROW DOWN
<Multi_key> <v> <bar> : "↓" U2193 # ARROW DOWN
<Multi_key> <asciicircum> <asciicircum> <J> : "☂" U2602 # UMBRELLA
note that the SKULL AND CROSSBONES binding is upper-case, as distinct
from the already-existing lower-case binding for ¤.
☠☠☠,