Returning query/table into a variable - sql

Question

Following the instructions from here, I am trying to return the results of a query into a variable like so
DROP DATABASE IF EXISTS test;
CREATE DATABASE test;
\c test
CREATE TABLE staff(
id BIGSERIAL PRIMARY KEY,
first_name VARCHAR(50),
last_name VARCHAR(50),
age SMALLINT
);
CREATE FUNCTION get_contacts(
p_id_min BIGINT,
p_id_max BIGINT,
p_age_min BIGINT,
p_age_max BIGINT
)
RETURNS #contacts TABLE (
first_name VARCHAR(50),
last_name VARCHAR(50)
)
AS
BEGIN
INSERT INTO #contacts
SELECT
first_name,
last_name
FROM
staff
WHERE
id >= p_id_min
AND
id <= p_id_max;
INSERT INTO #contacts
SELECT
first_name,
last_name
FROM
staff
WHERE
age >= p_age_min
AND
age <= p_age_max;
RETURN;
END;
But I am getting the following error
DROP DATABASE
CREATE DATABASE
You are now connected to database "test" as user "postgres".
CREATE TABLE
psql:test.sql:31: ERROR: syntax error at or near "#"
LINE 5: RETURNS #contacts TABLE (
^
psql:test.sql:33: ERROR: syntax error at or near "RETURN"
LINE 1: RETURN;
^
psql:test.sql:34: WARNING: there is no transaction in progress
COMMIT
I have 2 questions:
Why am I getting the syntax error at or near "#" and how do I fix thix?
What is the significance of # at the beginning of a variable name?

Answer 1

Turns out, in Postgres, the RETURN command can be used multiple times, so I just did the following
CREATE FUNCTION get_contacts(
p_id_min BIGINT,
p_id_max BIGINT,
p_age_min BIGINT,
p_age_max BIGINT
)
RETURNS TABLE(
id BIGINT,
first_name VARCHAR(50),
last_name VARCHAR(50),
age SMALLINT
)
AS $$
BEGIN
--RETURN FIRST QUERY
RETURN QUERY
SELECT * FROM staff
WHERE id >=p_id_min AND id<=p_id_max;
--DO OTHER WORK
...
--RETURN SECOND QUERY
RETURN QUERY
SELECT * FROM staff
WHERE age >=p_age_min AND age<=p_age_max;
END $$ LAnguage 'plpgsql';

Answer 2

Author was initially using # for parameters. For code you might also try this
CREATE FUNCTION get_contacts(
p_id_min BIGINT,
p_id_max BIGINT,
p_age_min BIGINT,
p_age_max BIGINT
)
RETURNS TABLE (
first_name VARCHAR(50),
last_name VARCHAR(50)
)
AS $$
BEGIN
INSERT INTO #contacts
SELECT
first_name,
last_name
FROM
staff
WHERE
id >= p_id_min
AND
id <= p_id_max;
INSERT INTO #contacts
SELECT
first_name,
last_name
FROM
staff
WHERE
age >= p_age_min
AND
age <= p_age_max;
RETURN;
END;