Each entity in an AutoCAD file may have Extension Records (XRecords) in an associated extension dictionary. This data is typically used by applications to store attribute information, and is similar to the Extended Entity Data that may be associated with an entity.
The reading of XRecord data is related to the reader parameter Entity XRecord Data Reading. When Entity XRecord Data Reading is enabled (which sets it to Lists), the AutoCAD reader stores XRecord data similarly on read to extended entity data, using the same List form. The AutoCAD writer supports the creation of XRecord using the List form of XRecord data attributes.
XRecord data that is read as lists is different from Extended Entity Data in the following ways:
- XRecord attribute names start with autocad_xrecord_data* instead of extended_entity_data*.
- XRecord data is not read in the Interpreted form.
- XRecord data has a name for each XRecord entry in the extension dictionary of an entity. This is stored as xrecord_name, and parallels the alternative application_name used in Extended Entity Data.
See the Extended Entity Data section for more information.