The default SQL schema has the following constraint for entity_remarks:
CONSTRAINT 'fk_entity_remarks_remark1'
FOREIGN KEY ('rem_id')
REFERENCES 'rdap'.'remark' ('rem_id')
ON DELETE NO ACTION
ON UPDATE NO ACTION)`
Due to this entity remarks can be used only once. I doubt that this is the intended behaviour, at least dropping the constraint allows to re-use remarks just fine. IMHO the constraint should be dropped or extended to ent_id