How to revoke access and list schema objects

Hi,

There are are some people who use my database and I want to prevent them
to read code of tables and funtions. I have created a schema in which
only postgres user can have access. Other users can not use objects in
this but they can list all sql code for each object if they use pgadmin.
What is the command to prevent users to list objects and prevent them to
read the sql code.

Thanks