ask for help: _NDIS_ADAPTER_BLOCK,_NDIS_MINIPORT_BLOCK

I am now implemented ndis hooking driver.I found

2000 ndis ddk define
_NDIS_MAC_BLOCK
_NDIS_ADAPTER_BLOCK
_NDIS_PROTOCOL_BLOCK
_NDIS_OPEN_BLOCK
_NDIS_MINIPORT_BLOCK
and the third pointer of _NDIS_OPEN_BLOCK is
PNDIS_ADAPTER_BLOCK AdapterHandle;
// pointer to our adapter

xp ndis ddk define:
_NDIS_MAC_BLOCK
_NDIS_MINIPORT_BLOCK
_NDIS_PROTOCOL_BLOCK
_NDIS_OPEN_BLOCK
and the third pointer of _NDIS_OPEN_BLOCK is
PNDIS_MINIPORT_BLOCK        MiniportHandle;    
// pointer to the miniport

question:
_NDIS_MINIPORT_BLOCK is defined in 2000 ndis ddk, why not use PNDIS_MINIPORT_BLOCK as the third pointer of _NDIS_OPEN_BLOCK.
I am a little confused, who can help explain the difference between NDIS_MINIPORT_BLOCK and _NDIS_ADAPTER_BLOCK and when and how they are used?

Thanks a lot

I am now implemented ndis hooking driver.I found

2000 ndis ddk define
_NDIS_MAC_BLOCK
_NDIS_ADAPTER_BLOCK
_NDIS_PROTOCOL_BLOCK
_NDIS_OPEN_BLOCK
_NDIS_MINIPORT_BLOCK
and the third pointer of _NDIS_OPEN_BLOCK is
PNDIS_ADAPTER_BLOCK AdapterHandle;
// pointer to our adapter

xp ndis ddk define:
_NDIS_MAC_BLOCK
_NDIS_MINIPORT_BLOCK
_NDIS_PROTOCOL_BLOCK
_NDIS_OPEN_BLOCK
and the third pointer of _NDIS_OPEN_BLOCK is
PNDIS_MINIPORT_BLOCK        MiniportHandle;    
// pointer to the miniport

question:
_NDIS_MINIPORT_BLOCK is defined in 2000 ndis ddk, why not use PNDIS_MINIPORT_BLOCK as the third pointer of _NDIS_OPEN_BLOCK.
I am a little confused, who can help explain the difference between NDIS_MINIPORT_BLOCK and _NDIS_ADAPTER_BLOCK and when and how they are used?

Thanks a lot
 

NDIS_ADAPTER_BLOCK and NDIS_MAC_BLOCK is used in old ndis version（3.xx).
NDIS_MINIPORT_BLOCK was imported in ndis 4.00

miniport_block is used for handling miniport driver operation,such as handling interrupt,indicating received network data or status to binding protocol, ...., protocol driver use open_block to relate to  miniport driver for querying or setting status of miniport driver or sending network data .