sentences:  The first releases on HatHut between 1975 and 1979 had alphabetic catalog numbers starting with A and ending with a triple LP Y/Z/Z making a total of twenty albums in the series.From 1980 to 1981, following the last alphabetic catalog number, HatHut releases had a written numeric catalog number followed by a bracketed "RO" code where the first digit of the code indicated a single ("1RO"), double ("2RO") or triple ("3RO") LP.A total of 22 albums were released in this series.