Step 1: In disaster management, casualties are sorted by colour tags so that limited resources reach those who benefit most.
Step 2: Under the standard four-colour scheme, Red marks the critically injured needing immediate care, Yellow marks delayed but serious cases, Black marks the dead or hopeless, and Green marks the walking wounded.
Step 3: The green-tagged group are ambulatory patients - they can walk and have minor injuries, so their treatment can safely be deferred.
Step 4: Since high priority is Red and the lowest priority moribund group is Black, the green code corresponds to ambulatory patients.
\[\boxed{\text{Ambulatory}}\]