Family Group Sheets only provide basic information (birth, death and marriage, etc). More detail about an individual can be obtained by selecting "More on this person" beside his/her name.
<3> is Primary (e.g. An Official Certificate) <2> is Secondary (e.g. A Headstone, Fellow Researcher, etc) <1> is Questionable (e.g. A Family Story) <0> is Unreliable (Not Trusted)