nce field of the chosen parity from the ordered list of frames refFrameListXShortTerm is inserted into RefPicListX. When there are no more short-term reference fields of the alternate parity in the ordered list of frames refFrameListXShortTerm, the next not yet indexed fields of the available parity are inserted into RefPicListX in the order in which they occur in the ordered list of frames refFrameListXShortTerm. 2. Long-term reference fields are ordered by selecting reference fields from the ordered list of frames refFrameListLongTerm by alternating between fields of differing parity, starting with a field that has the same parity as the current field (when present). When one field of a reference frame was not decoded or is not marked as "used for long-term reference", the missing field is ignored and instead the next available stored reference field of the chosen parity from the ordered list of frames refFrameListLongTerm is inserted into RefPicListX. When there are no more long-term reference fields of the alternate parity in the ordered list of frames refFrameListLongTerm, the next not yet indexed fields of the available parity are inserted into RefPicListX in the order in which they occur in the ordered list of frames refFrameListLongTerm. 8.2.4.3 Modification process for reference picture lists When ref_pic_list_modification_flag_I is equal to 1, the following applies: 1. Let refIdxL0 be an index into the reference picture list RefPicList0. It is initially set equal to 0. The corresponding syntax elements modification_of_pic_nums_idc are processed in the order they occur in the bitstream. For each of these syntax elements, the following applies: If modification_of_pic_nums_ido is equal to 0 or equal to 1, the process specified in subclause 8.2.4.3.1 is invoked with refIdxL0 as input, and the output is assigned to refldxL0. Otherwise, if modification_of_pic_nums_ido is equal to 2, the process specified in clause 8.2.4.3.2 is invoked with refldxL0 as input, and the output is assigned to refldxL0. Otherwise (