Alan was responsible for setting up this guideline specifically for the Member Trips forum. Basically, saying the date and train of travel is OK as long as the specific accommodation is not mentioned. Mentioning a train and a specific car and room is OK as long as the exact date of travel is not mentioned. Of course, saying anything you want through PM to others you know well is just fine.
Actually, while I wrote up the rules, it was something that Anthony and I both discussed and agreed upon, prior to creating the forum.
And in addition to some of the other reasons expressed by PRR 60 and others, there was another reason that we insisted on the no room number's rule. Amtrak employees.
While most Amtrak employees are decent people and do their jobs, like any company there is always the potential for bad apples to slip in. A bad apple working as a reservation agent for example, can take that date, car, & room number and find your reservation in ARROW. Said agent then has access to your name, itinerary, and more importantly your home address. Said agent now sells that info to a thief he just happens to know, and viola, you come home to an empty house.
Yes, technically they can do that anyhow just by pulling up a train's inventory. But that way they don't know for certain that no one will be home. Whereas, someone saying "I'm taking my entire family on #29 on the 13th in the F room" pretty much guarantees the house will be empty.
I grant that this isn't a highly likely scenario, but it is still entirely possible. Additionally, an employee could remember that you gave them a bad review and know that you're coming again and where to find you on the train. While all of this is speculation and nothing more, Anthony & I felt that this policy was the best. We also felt that it would encourage more people to participate in the special forum, since it would be your choice on whether or not to meet up with an interested party. If you post the number in the clear, you have no choice. The other person knows where to find you.
This way, if you get a PM from someone seeking a meet up, you can say yes and provide info. You could pick to meet in the lounge and say "I'll be wearing X baseball cap". Or you could choose to simply say no or even ignore the PM.
So the policy is what it is and it will remain so for the foreseeable future as we feel that this is what is best for the forum and our members & guests.