The Translation (T) and Rotation (R) options let you modify translation or rotation keyframe animation specifically.

When both options are active, you can modify all keyframes for translation and rotation at the current time. When only one of the options is active, you can modify the keyframes of either translation or rotation at the current time, without modifying the other keyframes.

You can also modify the keyframe animation of a specific axis for translation and rotation. For example, the following figure shows a situation in which only the keyframe animation for Translation along the Y axis and Rotation along the Z axis is modified (refer to B and C). The other translation and rotation animation is not modified.

Dynamic Editor A. Translation and Rotation options B. Keyframe animation for translation along the Y axis C. Keyframe animation for rotation along the Z axis

The Translation and Rotation options are disabled when keyframes are selected in the FCurves or Dopesheet windows. See Status indicator for more information.