In my experience as founder of a 20 plus employee start-up, I assumed all employees would find out each other's salary. There is no way to enforce secrecy, people talk. For exactly this reason it is better to have a clear policy. Having 20 different special deals - like "I want to work one month less, but get paid less" etc - means you spend all of your time managing HR. Everyone thinks the other person's deal is better. Absolute nightmare to manage. Much better to transparently say "This is what we pay, this is what we offer in terms of benefits / flexibility (location, time off, etc). If that matches your needs, great. If not, we are not the right employer for you."