Use the Edit User-Defined File References dialog box to change or remove references you have added to a file.
To display this dialog box:
On the file's Contains tab, click Custom References 
.
Toolbar Buttons
Some commands accessed from toolbar buttons are also available on the shortcut menu.
File List
To control the column display in the table, right-click any column heading and select or clear the available columns.
| Type |
Displays a thumbnail preview of the file when you hover over the file type icon. |
| File name |
Selected file and files referenced by it. |
| Referenced |
Indicates whether files are referenced. |
| Show in Bill of Materials |
Includes the file in the parent file BOM. |
| Quantity |
Quantity of the referenced file. |
| Found in |
Location of the referenced files. |
Shortcut Menu Options
Right-click in the file list to access these menu options:
| Columns |
Lets you add or remove columns. |
| Show Reference Selection Controls |
For files with references (such as assemblies with parts), turns on a second check box to the right of parent files. Use the left check box to select or clear only the parent file.
Use the right check box to select or clear the parent file and all of its references.
If all check boxes are not in the same state, the added check box displays  .
|
| Select All |
Selects all files, so that you can check or clear the Referenced or Show in Bill of Materials columns. |
| Select Files |
Displays a dialog box where you can specify wildcards to select a group of files. You can then use a single keystroke to check or clear the files in the Referenced or Show in Bill of Materials columns. |
| Show Tree Lines |
Adds tree lines to the File name column. |