The following table provides summary descriptions of the AutoLISP extended data-handling functions.
| Extended data-handling functions | Platform | |||||
|---|---|---|---|---|---|---|
| Windows | Mac OS | Web | ||||
| Function | Description | AutoCAD | AutoCAD LT | AutoCAD | AutoCAD LT | AutoCAD | 
| Registers an application name with the current AutoCAD drawing in preparation for using extended object data | ✓ | ✓ | ✓ | -- | ✓ | |
| Returns the amount of extended data (xdata) space that is available for an object (entity) | ✓ | ✓ | ✓ | -- | ✓ | |
| Returns the size (in bytes) that a list occupies when it is linked to an object (entity) as extended data | ✓ | ✓ | ✓ | -- | ✓ | |