Keying Flag Items

INSERTKEY_NEEDED:

Only Needed.

Only insert keyframes where they’re needed in the relevant F-Curves.

INSERTKEY_VISUAL:

Visual Keying.

Insert keyframes based on ‘visual transforms’.

INSERTKEY_XYZ_TO_RGB:

XYZ=RGB Colors (ignored).

This flag is no longer in use, and is here so that code that uses it doesn’t break. The XYZ=RGB coloring is determined by the animation preferences..