Hi Caroline,
thanks for the documents. The Product Notice (PN) is quite useful. 
As I understand it, the PN gets updated with progressing processing baseline versions. The current baseline version is v2.37 (IPF v6.16), applied from Aug02 (ie fairly fresh). Are there PNs for earlier baseline versions available? I couldn’t find any in the Document libraries.
Also, how can I see which baseline version my data has? If I understand correctly, the product name only contains the major baseline version number. Is the minor one anywhere in the data, too? where?
And, I keep struggeling with understanding the different cloud flags/masks. The PN speaks of “Bayesian cloud mask” (providing probability 0-1) and of “the probabilistic cloud mask” (which does currently not provide probabilities over land). From the PN it seems to me these are two different items. However, looking at the data, I come to the conclusion that this is one and the same thing - the values/array stored in the “probability_cloud” items in the flags*.nc files. Is that so?
Then, there are the “bayes” items in the flags*.nc, which in contrast to “probability_cloud” are bit masks. What is their meaning, and how are they derived (considering that they cover land, too, they seem closer related to the base cloud mask…)? I can not really get that from the short name/description in the data itself or the SLSTR PDFS (or the web-based User and Technical Guides).
I kind of asked these latter questions already there, but asking you directly here probably yields better results… 
Thanks & best wishes!