IPPPSSOOT

The naming convention for Space Telescope Observations where:
N : Instrument character (N for NICMOS)

PPP : Program_id (3 characters)

SS : Obset_id (2 characters)

OO : Ob_number (2 characters)

T : Type (1 character, usually (r|o|t))

Associations have a similar naming convention:
N : Instrument character (N for NICMOS)

PPP : Program_id (3 characters)

SS : Obset_id (2 characters)

AA : Association_id (2 characters)

N : Product_id (1 number (0: target))