As usual, I had a client with a very specific request for their Joomla website: they had some forms on their website that they didn't want accessible to the general public. Furthermore, they didn't want their clients to have to register. Instead, they preferred to have one password to protect these forms. If they wanted a client to have access to the forms, they would send the password to the client. I did a Google search and found MosPasswort Plugin for Joomla.