This may seem a pointless command at first but at has it's uses.
When an explicit object ID is represented, it should ideally be preceded by "#:".
This tells the system that it is an object id and not just some random number.
This is only strictly necessary if the code is to be used as part of an application where the ID might be changed when the code is ported to another organisation but it does help readability in general code.
When the code containing an ID is run, it removes the prefix but only if it is within a command parameter.
It will not be removed if it is used elsewhere such as in a property of an HTML tag. That's where this command comes in.
|1||obj_id||Current Object ID||Integer||The Object ID to return|