MIMIC-IV non-consecutive ICU stays stay_id

[mdbotto]

It says in the PhysioNet article the following:

Importantly, non-consecutive ICU stays remain as unique stay_id in the icustays table. In some cases, these could be considered the "same" ICU stay as the patient was transferred out for a planned procedure. In other cases, these are unanticipated readmissions to the ICU. As there was no systematically perfect method to differentiate these cases, we did not attempt to merge non-consecutive stay_id, and it is up to the investigator to appropriately handle these cases.

What is the definition of a non-consecutive ICU stay? I don't quite get if a patient that leaves the ICU and comes back is assigned a new stay_id or not.
What is the criteria for not assigning a new stay_id (or what is criteria for assigning a new stay_id)? I am planning to study ICU readmission, and want to separate planned procedures from unanticipated readmissions.

[mdbotto]

I misinterpreted the text. Every time a patient enters the ICU a new stay_id will always be assigned, right? Apologies!