Katana 3.5v5 docs:

RendererProceduralAssign

The RendererProceduralAssign node allows you to assign renderer procedurals to specific locations in the scene.

Connection Type	Connection Name	Function
Input	in	The place in the node graph where you want to assign renderer procedurals.

Control (UI)	Default Value	Function
CEL	N/A	Sets the CEL specification of scene graph locations on which the assignment acts. The scene graph locations are specified using the Collection Expression Language (CEL). The CEL parameter options are available by clicking Add Statements. For more information, refer to the CEL Reference document found on the documentation HTML page (accessed through Help > Documentation) or the CEL Statement Widget Type in Common Parameter Widgets.
rendererProceduralAssign	N/A	Specifies which procedural to assign. Typically, you'll middle-mouse drag this from under /root/materials/proc in the scene graph. The rendererProceduralAssign parameter options are available by clicking the dropdown menu. For more information, refer to the Scene Graph Location Widget Type in Common Parameter Widgets.

Control (UI)

Default Value

Function

CEL

N/A

Sets the CEL specification of scene graph locations on which the assignment acts.

The scene graph locations are specified using the Collection Expression Language (CEL). The CEL parameter options are available by clicking Add Statements.

For more information, refer to the CEL Reference document found on the documentation HTML page (accessed through Help > Documentation) or the CEL Statement Widget Type in Common Parameter Widgets.

rendererProceduralAssign

N/A

Specifies which procedural to assign. Typically, you'll middle-mouse drag this from under /root/materials/proc in the scene graph. The rendererProceduralAssign parameter options are available by clicking the dropdown menu.