You can control access to a document by implementing a password for it. Passwords are case-sensitive and can be a maximum of 15 characters long. Create a strong password, ideally one that you can easily remember. But in case you might forget, you should also keep a copy of it in a safe place. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.