As with all headers, the first 8 bytes are composed of the header type (0x88) and the 7 byte kate signature ("kate\0\0\0").
Next, we find a variable length integer, holding the number of predefined font ranges this header contains. A negative value is an error.
Next, we find a list of font range definitions, as many as defined int the previously read number.
Next, we find a variable length integer, holding the number of predefined font mappings this header contains. A negative value is an error.
Next, for each predefined font mapping:
Next, the data ends.