field selection for material master.

hello Gurus,

i was making a material type and i gave material specific field ref as 0001, industry specific field ref as ROH and transaction specific field reference as MM01.

when i check the"maintain field selection for data screen" in IMG setting. it is showing me that MRP controller, Mrp type etc fields are optional (for all these field ref) but when i am trying to create that material of this type it is showing me all these fields as required,

can you tell me what is my mistake, is there any other field referene base

regards