&lcfilter is used for certain tables where we need to filter off records. It is taken from a property within the form itself. It is populated during programming time.
The values typically consist of the where clause portion of a SQL. Example : "where inv_type='C'" (denoting cash invoices) etc. However, when used in the search, the "where" word is stripped hence the scan will contain values with "and inv_type='C'".
Hope this clarifies the position.
Yau