In Qlik Replicate when you are running a target replication from a logstream repository, information such as this is noted in the log file regarding the position of the replication in the log stream repository:
500;637477859264524360;20210111084947867861
This number represents a very specific stream position in transaction data. Currently, you cannot restart a target replication from logstream using a transaction ID like SCN or LSN, you must restart from timestamp which involves in most cases some guesswork.
The ability to restart from this specific transaction identifier would enable greater parity with using logstream versus replication that is directly attached to a source, where transaction id restarts are supported.