As reported on CAMEL-16517, unavailable annotation parameters(hasHeader, hasFooter, isHeader, isFooter) are listed on "48.7. 4. FixedLengthRecord"
https://access.redhat.com/documentation/en-us/red_hat_fuse/7.8/html/apache_camel_component_reference/bindy-dataformat#four_fixedlengthrecord

Please consider to update the explanation for @FixedLengthRecord options.
ex:

 @FixedLengthRecord(header = X.class, footer = Y.class)