RFID T5557 synchronisation pattern

I am writing software for RFID reader. Previously I made firmware for 125kHz Unique cards, and it was easy to catch synchronisation, because it consists of 9 '1' bits, and it is guaranteed that this sequence does not repeat in bitstream. Now I want to redesign firmware for T5557 cards. Specification is quite explanatory, but I cann't find any info about how to detect begining of each 32 bit block. Even when "Sequence Terminator" is enable, there is always possibility to write data which will have four followind '1' bits. Is there anything in datasheet that I am missed?