“Other devices” means manually-emplaced munitions and devices including improvised explosive devices designed to kill, injure or damage and which are actuated manually, by remote control or automatically after a lapse of time.
It is prohibited to use booby-traps or other devices in the form of apparently harmless portable objects which are specifically designed and constructed to contain explosive material.
“Booby traps and other devices” is one legal thing, there’s no legal distinction. Pager bombs are always a war crime regardless of circumstances.
That’s only because they’re designed with passivation to vent tanks and disconnect batteries to remove sources of explosion when they start to die. If that fails the tanks eventually pop from thermal cycling or the solar panels overcharge the battery until it blows up like a Russian satellite did earlier this year.