What is the term for the small staff from which the commissioning pennant is flown?

The term for the small staff from which the commissioning pennant is flown is referred to as a "gaff." The gaff is typically a horizontal beam or spar attached to the mast of a ship, and it serves as a support for flags or pennants, including the commissioning pennant. It is common to see the commissioning pennant flown from the gaff during significant occasions, such as when a vessel is commissioned or in recognition of certain honors.

The other terms presented refer to different items or concepts. A pennon generally refers to a small flag or banner that is often used in heraldry or military contexts, while the term pigstick does not pertain to maritime flags or standards. The staff, while it can denote any vertical support for a flag, is not the specific term used for the gaff in naval and maritime contexts. Thus, gaff correctly identifies the small staff where the commissioning pennant is traditionally displayed.