A sense of history and security concerns are changing some of the rules about the joint address to Congress that President Obama will give tonight, as they apply to members.
This was recently released by the office of House Majority Leader Steny Hoyer (D-Md.):
After consultation among the Speaker and the Majority and Minority Leaders, and with their consent, when the two Houses meet tonight in joint session to hear an address by the President of the United States, only the doors immediately opposite the Speaker and those immediately to her left and right will be open.
No one will be allowed on the floor of the House who does not have the privilege of the floor of the House. Due to the large attendance that is anticipated, the rule regarding the privilege of the floor must be strictly enforced. Children of Members will not be permitted on the floor. The cooperation of all Members is requested.
The practice of reserving seats prior to the joint session by placard will not be allowed. Members may reserve their seats only by physical presence following the security sweep of the chamber.
–Mike Soraghan