Softimage SDK Programmer's Guide > Customizing Softimage using the SDK > Custom ICENodes >

# Limitations

## Data Type

The following port data types are not supported for custom ICENodes:

- siICENodeDataLocation

- siICENodeDataExecute

- siICENodeDataReference

## Data Access

In general, calls to C++ API methods for accessing and creating scene objects is not recommended during the evaluation of ICENodes. It is not recommended to use any of the object model or scripting commands during an evaluation either, as Softimage may become unstable due to possible operator cycles, topology changes or multi-threading issues.

## Port and Group Identifiers

Port and group identifiers must not be modified or removed once the ICENode has been deployed and saved in a scene. Failure to do so may break backward compatibility of older scenes with the current version of the ICENode.