Host variables are used to pass information
between an application program and ALLBASE/SQL. They are ordinary
application program variables that happen to be used in SQL commands.
A host variable name must be preceded by a colon (:) when
used in an SQL command. When used elsewhere in an application program,
no colon should be used.
Host variable names must conform to ALLBASE/SQL's rules for
basic names; however, they are allowed to be up to 30 bytes in length.
In addition, host variable names must conform to the rules of the
language in which the application program is written.
