Field name & is not a valid ABAP Dictionary name ("-" missing)

The element name does not contain a hyphen. It cannot therefore be
identical with the name of a table field from the ABAP Dictionary.
The element has no link to the ABAP Dictionary.
Change the name of the element so that it is the same as that of a
table field in the ABAP Dictionary.

Error message extract from SAP system. Copyright SAP SE.