/* Output ID list. */
raf.writeByte(ZoneInfoFile.TAG_ZoneIDs);
block_size = 2;
raf.writeShort(block_size & 0xFFFF);
short nID = 0;
raf.writeShort(nID & 0xFFFF);
for (int i = 0; i < roi_size; i++) {
for (String key : roit.get(i)) {
byte size = (byte)key.getBytes("UTF-8").length;
raf.writeByte(size & 0xFF);
raf.write(key.getBytes("UTF-8"), 0, size);