[Daniel Westermann <daniel.westermann@dbi-services.com>]

postgres@pgbox:/u01/app/postgres/local/dmk/ [PG961] pg_dumpall -V 
pg_dumpall (PostgreSQL) 9.6.1 
postgres@pgbox:/u01/app/postgres/local/dmk/ [PG961] pg_dumpall --help 
pg_dumpall extracts a PostgreSQL database cluster into an SQL script file. 

Usage: 
pg_dumpall [OPTION]... 

General options: 
-f, --file=FILENAME output file name 
-V, --version output version information, then exit 
--lock-wait-timeout=TIMEOUT fail after waiting TIMEOUT for a table lock 
-?, --help show this help, then exit 

Options controlling the output content: 
-a, --data-only dump only the data, not the schema 
-c, --clean clean (drop) databases before recreating 
-g, --globals-only dump only global objects, no databases 
-o, --oids include OIDs in dump 
-O, --no-owner skip restoration of object ownership 
-r, --roles-only dump only roles, no databases or tablespaces 
-s, --schema-only dump only the schema, no data 
-S, --superuser=NAME superuser user name to use in the dump 
-t, --tablespaces-only dump only tablespaces, no databases or roles 
-x, --no-privileges do not dump privileges (grant/revoke) 
--binary-upgrade for use by upgrade utilities only 
--column-inserts dump data as INSERT commands with column names 
--disable-dollar-quoting disable dollar quoting, use SQL standard quoting 
--disable-triggers disable triggers during data-only restore 
--if-exists use IF EXISTS when dropping objects 
--inserts dump data as INSERT commands, rather than COPY 
--no-security-labels do not dump security label assignments 
--no-tablespaces do not dump tablespace assignments 
--no-unlogged-table-data do not dump unlogged table data 
--quote-all-identifiers quote all identifiers, even if not key words 
--use-set-session-authorization 
use SET SESSION AUTHORIZATION commands instead of 
ALTER OWNER commands to set ownership 

Connection options: 
-d, --dbname=CONNSTR connect using connection string 
-h, --host=HOSTNAME database server host or socket directory 
-l, --database=DBNAME alternative default database 
-p, --port=PORT database server port number 
-U, --username=NAME connect as specified database user 
-w, --no-password never prompt for password 
-W, --password force password prompt (should happen automatically) 
--role=ROLENAME do SET ROLE before dump 

If -f/--file is not used, then the SQL script will be written to the standard 
output. 

Report bugs to <pgsql-bugs@postgresql.org>. 

It is mentioned in the documentation but not in the help output 

Regards 
Daniel