You can use the Bookmark property with forms to set a bookmark that uniquely identifies a particular record in the form's underlying table, query, or SQL statement.
Setting
The Bookmark property contains a string expression created by Microsoft Access.
You can set this property by using a macro or Visual Basic.
Note You get or set the form's Bookmark property separately from the ADO Bookmark or DAO Bookmark property of the underlying table or query.
Remarks
When a bound form is opened in Form view, each record is assigned a unique bookmark. In Visual Basic, you can save the bookmark for the current record by assigning the value of the form's Bookmark property to a string variable. To return to a saved record after moving to a different record, set the form's Bookmark property to the value of the saved string variable. You can use the StrComp function to compare a Variant or string variable to a bookmark, or when comparing a bookmark against a bookmark. The third argument for the StrComp function must be set to a value of zero.
Note Bookmarks are not saved with the records they represent and are only valid while the form is open. They are re-created by Microsoft Access each time a bound form is opened.
There is no limit to the number of bookmarks you can save if each is saved with a unique string variable.
The Bookmark property is only available for the form's current record. To save a bookmark for a record other than the current record, move to the desired record and assign the value of the Bookmark property to a string variable that identifies this record.
You can use bookmarks in any form that is based entirely on Microsoft Access tables. However, other database products may not support bookmarks. For example, you can't use bookmarks in a form based on a linked table that has no primary index.
Requerying a form invalidates any bookmarks set on records in the form. However, clicking Refresh on the Records menu doesn't affect bookmarks.
Since Microsoft Access creates a unique bookmark for each record in a form's recordset when a form is opened, a form's bookmark will not work on another recordset, even when the two recordsets are based on the same table, query, or SQL statement. For example, suppose you open a form bound to the Customers table. If you then open the Customers table by using Visual Basic and use the ADO Seek or DAO Seek method to locate a specific record in the table, you can't set the form's Bookmark property to the current table record. To perform this kind of operation you can use the ADO Find method or DAO Find methods with the form's RecordsetClone property.
An error occurs if you set the Bookmark property to a string variable and then try to return to that record after the record has been deleted.
The value of the Bookmark property isn't the same as a record number.