psql variables in the DO command

Hello,

I can't use psql variable in the DO command. Is it intentional behavior?

postgres=# \set var 'Hello, World!'

postgres=# do $$begin raise notice '%', :'var'; end;$$;

ERROR:  syntax error at or near ":"

LINE 1: do $$begin raise notice '%', :'var'; end;$$;

                                      ^


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Pavel Luzanov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company