Are there any requirements for landing stairs and floors? Note that it is not a rest platform.

The requirements are the same. Stair platform and semi-platform are both rest platforms of stairs. In addition, it should be noted that when the door is open, the effective evacuation width of the platform cannot be blocked.

The word "should not" is mandatory and must not be violated. "Inappropriate" is a rule that can be done or not.

For details, please refer to the staircase regulations in General Principles of Civil Buildings.