This key-in and switches can be used with the Batch Process Utility as described in IFC - Batch Export to IFC using the Batch Processor.
All your commands will generally start with ifcout * unless you need to apply a specific name, the * takes the source DGN filename as the name of the output IFC.
There are six switches, corresponding to drop-down or tick box options in the IFC Export dialog, that can be applied to this key-in, they have a short and long form, e.g.: 'c' or 'cobie'.
They also have arguments to control their operation, e.g.: 'm:FMH' or 'mvd:FMH'
If no switches are applied their defaults will be applied:
The result of the key-in 'ifcout *' command would be to create and optimise an IFC file using the IFC 2x3 Coordination View 2.0 Model View Definition.
As I would always optimise the IFC, in most cases the switches only need to be applied if you need to output to the FM Handover Model View Definition and/or create COBie output or i-models.
In the batch convert context it will probably be more useful to zip the files afterwards rather than have individual zip files (depending on the sizes of your outgoing IFC of course) so you may not need to use the z switch.
While testing the switches I have found that in AECOsim Building Designer SS6 the c switch will always create an i-model unless told not to by stating c:0 (or cobie:0), a defect has been filed to address this problem.