Keyframe spreadsheet - what are little side arrows?

In the Keyframe spreadsheet area, what are the little sideways-pointing arrows?

My intention is that all these shapes are merely static diagrams, and I have not intentionally added any animation keyframes.

Here, the little arrows point left and right, but in the manual, some only point one way.

What are these arrows used for?

arrows.jpg (311.09 KiB) Viewed 1326 times

I did check the Manual, and came across the page where these little arrows are illustrated, but could not see what the arrows are.

manual.jpg (171.95 KiB) Viewed 1326 times

I believe they indicate that the node has data available in that direction, but it's outside the range of the composite. That is, if the Global range of the tool is greater than the Global range of the comp.

I believe they indicate that the node has data available in that direction, but it's outside the range of the composite. That is, if the Global range of the tool is greater than the Global range of the comp.

Thanks. Can you clarify what is meant by "global range" of a tool/node/composition? Can you give an example?

If you have 1 clip as MediaIn1 and another longer clip as MediaIn2 both connected to a Merge node, the longer clip will show the arrow at the end because it's entire length is not part of the comp.

If you have 1 clip as MediaIn1 and another longer clip as MediaIn2 both connected to a Merge node, the longer clip will show the arrow at the end because it's entire length is not part of the comp.

Thanks. I understand the logic of little arrows applies in your example of MediaIn1 being shorter than MediaIn2.

But in my example, each item in my Fusion composition, with little arrows, are static Polygon shapes, with no time-related keyframes. I wonder how the little arrows concept applies to my situation?

All nodes have a Global Range, but not all of them have a control for it in the Inspector. The mask tools are valid at all frames by default, but they don't have to be. If you grab the end of that bar in the Keyframes view and drag it just slightly inward, the out-of-range indicator will vanish. If you then extend the Global Out of the composition, you'll see that the mask tool no longer lengthens automatically to fill the entire range.