Interestingly, Nitroso-Indapamide = Indapamide Impurity A is included in the Ph. Eur. Indapamide monograph with a limit of 5 ppm. It appears as a contradiction to deal with.
There was a previous discussion on the topic on the site
N-Nitrosoiminodiacetic acid and N-nitroso-ethylenediamine-triacetic acid are included with an AI of 1.5µg/day, originating from Isosorbide mononitrate. N-Nitrosoiminodiacetic acid has negative data in LCDB, however they are not considered reliable.