BINDTYPE system variable
Xref bind type
Specifies the handling of xref names when binding xrefs or when xrefs are edited in-place. If the BINDTYPE variable = 1 (Insert-like behavior), Xrefs will be converted into blocks. If BINDTYPE = 0 (traditional binding behavior), it binds the xref and makes the xref part of the drawing (the objects/layers from the external drawing will be added to the current drawing with the prefix equal to the file name).
Off (0): Traditional binding behavior
On (1): Insert-like behavior