Characteristics
Before the arrival of the mobile emitter, The Doctor's holo-program was confined only to the Sickbay and the holodecks.
Depending on the amount of hologram patterns he has and capacity of his pattern buffers, The Doctor sometimes has the ability to shapeshift.
The Doctor is also able to download his program and personality subroutines into a humanoid with Borg implants, thus possessing the functions and abilities of that individual. Such is the case when he was forced to hide within the body of Seven of Nine.
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