length is an unsigned integer literal designating the length in bytes.
Unlike the case for the CHAR FOR BIT DATA type, there is no default length for a VARCHAR FOR BIT DATA type. The maximum size of the length value is 32,672 bytes.
VARBINARY
An operation on a VARCHAR FOR BIT DATA and a CHAR FOR BIT DATA value (e.g., a concatenation) yields a VARCHAR FOR BIT DATA value.
The type of a byte literal is always a VARCHAR FOR BIT DATA, not a CHAR FOR BIT DATA.