The following  status icons are missing from the High Contrast Theme:

appointment-missed
appointment-soon
avatar-default
battery-caution
battery-caution-charging
battery-empty
battery-full-charged
battery-full-charging
battery-full
battery-good-charging
battery-good
battery-low-charging
battery-missing
changes-allow
changes-prevent
computer-fail
dialogue-password
folder-drag-accept
folder-open
folder-visiting
image-loading
mail-attachment
mail-read
mail-replied
mail-signed
mail-signed-verified
mail-unread
media-playlist-repeat
media-playlist-shuffle
microphone-sensitivity-high
microphone-sensitivity-low
microphone-sensitivity-medium
microphone-sensitivity-muted
network-error
network-idle
network-offline
network-receive
network-transmit
network-transmit-receive
network-wireless-disconnected
network-wireless-encrypted
printer-error
printer-printing
security-high
security-low
security-medium
software-update-available
software-update-urgent
task-due
task-past-due
user-available
user-away
user-busy
user-idle
user-invisible
user-offline
weather-clear-night
weather-clear
weather-few-clouds-night
weather-few-clouds
weather-fog
weather-overcast
weather-severe-alert
weather-showers-scattered
weather-showers
weather-snow
weather-storm