projection is one where the terrestrial "surface" is cut in
order to avoid the distortions that inevitably arise from projecting
the earth's three-dimensional surface onto a two-dimensional plane.
The map below shows an "interrupted projection"
with its center in the Pacific Ocean. I haven't been able to discover
or determine which particular projection is used.
On this map on an equal
projection the center is
The Scott catalog for this stamp from Brazil
identifies the map as a Mercator Map. If so, it is the only
interrupted version of a Mercator projection that I know of.