p 3 VAXELN Technical Summary
By this I mean that one can define a domain NAME and then define several fields based on this domain. Rdb makes no attempt, to my knowledge, to ensure that comparisons come from the same domain.
p 4-11 Rdb Reference Manual
p 6-33 Rdb Reference Manual
p 2-23 Database Design and Definition Manual
Personal opinion.
FIRST N is another useful clause. It only prints the first N records that fit the specification.
p 322 DATE An Introduction to Database Systems Date calls Rdb/VMS relationally complete.

Security, Privacy, Legal