The number of bytes to store the attribute; excluding the index into the constant pool for the name (2 bytes) and the length of the attribute (4 bytes).
The number of bytes required to store this attribute; including the index into the constant pool for the name (2 bytes) and the length of the attribute (4 bytes).
The attribute class defines the common elements of all attributes; i.e., basically the first two attribute_info elements.
attribute_info { u2 attribute_name_index; u4 attribute_length; u1 info[attribute_length]; ... }