The DISPLAY LIKE attribute applies column attributes defined in the database schema files (.att) to a field.
DISPLAY LIKE [table.]column
Specifying this attribute is equivalent to listing all the attributes that are assigned to table.column in the database schema file with the .att extension.
Display attributes are automatically taken from the schema file if the field is linked to table.column in the field name specification.
The DISPLAY LIKE attribute is evaluated at compile time, not at runtime. If the database schema file changes, recompile all forms using this attribute. Even if all of the fields in the form are FORMONLY, this attribute requires the form compiler to access the database schema file that contains the description of table.
EDIT f001 = FORMONLY.fullname, DISPLAY LIKE customer.custname;