Implemented CancelRequestItemService & parsing sequence number (not item sequence number)
Desired user or item info returned by toolkit can be set in toolkit.properties (NCIP cuts off desired services before can service parse them from initiation data)

Sequence number - see comments in parser (AlephRequestItemHandler.java)
Basically it is needed to build unique request ID (f.e. MZK500000004210000100001), where the last four numbers are the sequence number