Officially we were told there is a 30 day hold limit. However our local postmaster holds our mail for as long as we want. No paper work involved. We just let him know on what day we are leaving home.
One year we had it held for 82 days. Came home and started sorting mail. Never realized how much JUNK Mail is sent until then! :E
There should be away to accept first class mail only while at home or away. Unfortunately there isn't. :(
Mail forwarding wouldn't work for us. We never know where we are going to be or for how long. Besides, we never found it necessary.