Exploring CINEMA 4D R16 Studio Interface - MAXON CINEMA 4D R16 Studio: A Tutorial Approach - page 26

Figure 1-32 The right camera projection
Front
The Front option is used to display the XY view, as shown in Figure 1-33.
Back
The Back option is used to display the YZ view, as shown in Figure 1-34.
Figure 1-33 The front camera projection
Figure 1-34 The back camera projection