The RPC_BINARY_CONTAINER structure is a container for binary printer data and is used in the RPC_BIDI_DATA (section structure.<8>

 typedef struct _RPC_BINARY_CONTAINER {
   DWORD cbBuf;
   [size_is(cbBuf), unique] BYTE* pszString;

cbBuf: This member specifies the size, in bytes, of the buffer that is pointed to by the pszString member.

pszString: A pointer to an array of bytes that contain binary printer data.