  From 2004 to 2017, the Cassini spacecraft orbited Saturn, completing 127
close flybys of its largest moon, Titan. Cassini's Composite Infrared
Spectrometer (CIRS), one of 12 instruments carried on board, profiled Titan in
the thermal infrared (7-1000 microns) throughout the entire 13-year mission.
CIRS observed on both targeted encounters (flybys) and more distant
opportunities, collecting 8.4 million spectra from 837 individual Titan
observations over 3633 hours. Observations of multiple types were made
throughout the mission, building up a vast mosaic picture of Titan's
atmospheric state across spatial and temporal domains. This paper provides a
guide to these observations, describing each type and chronicling its
occurrences and global-seasonal coverage. The purpose is to provide a resource
for future users of the CIRS data set, as well as those seeking to put existing
CIRS publications into the overall context of the mission, and to facilitate
future inter-comparison of CIRS results with those of other Cassini
instruments, and ground-based observations.
