Section 7.5.4, "Attribute Encodings"
has a brief discussion of "constant"
which says there are 6 forms of constants.
It is incorrect in that it fails to mention (or count)
the block forms, which are clearly allowed by
section 4.1 "Data Object Entries" (see entry number 9 in
the numbered list, on constants).

Withdrawn, with the suggestion that the wording under the description of "constant" can be improved.