Chapter 12，In getdata payload ，What does a stand for Hash identifier？p

[windwindwa]

first of all, i think the Hash identifier is target hash of Type

[windwindwa]

first of all, i think the Hash identifier is target hash with Type of data item, but in the function of getdata.add_data(FILTERED_BLOCK_DATA_TYPE, b.hash()) which is in p205, the first parameter is merkle block, and the second parameter is blockhead's hash.
so,i think the second parameter is not target of first parameter hash.
i need helper ,wuwuwuuwwu

[windwindwa]

I decide