A series of reports on a wide range of onshore and offshore topics akin to articles. Reports had a year designation and then a running number e.g. 69/1, 69/2 etc. Some issues has a separate numbered sub-series as 'IGS short communications' consisting of a number of short articles. The series started with 69/1 and ended with 83/11. It was superceded in the same format but with a different numbering system by the BGS report series.