In G1, "full-young" GCs are GCs that collect only young regions, "partially-young" GCs are GCs that collect both young (eden / survivors) and old regions. We are not very happy with this terminology, especially the latter. So, we would like to rename them to "young" and "mixed". We should at least change all the output to conform to this terminology, i.e., it's not necessary to also change all variable names, comments, etc. - we can do that over time.