Generally new features are intended to be introduced in new first and second octets.So things like 1.8, 1.9, 1.10, 2.0, 2.1, etc would have new feature sets added.Where anything that's got a third or fourth octet are usually bug fixes, security patches, etc. (so like 1.8.1 or 1.8.1.1 or 1.9.1 or 1.9.3). Occasionally they break their own release schema, but generally speaking Chefkeks is right (or right enough so as to not worth mentioning). Or at least this is what they intend to move towards.