The custom databases that you can use for XDRefs must have the following features:
- They must be Microsoft Access database files.
- There must be a Long Integer field index column, which contains the point numbers, in each table in the database that can be used as an XDREF.
- Currently, only Integer, Long Integer, Single, Double, and Text type fields are supported.
- Any number of Tables can be defined in this database, but any that are referenced by XDRefs must have an index column defined.
- Any number of additional Text or Number columns may also be defined in this database table. There are no restrictions on the names and order of the columns after the index column.
- XDRefs are stored on the Settings tab in Toolspace under the Point collection.