There are a few core analyses that people do on repertoire sequence data. One is identifying germline genes and junctional boundaries, and there’s been a lot of thought about this by the VDJML team and a thread on this forum.
For BCR sequences, another core analysis is clustering sequences by naive rearrangement event, which are then variously called “clones”, “clonal families”, “lineages”, etc.
I’m not aware at any effort at standardization of a file format for those sorts of inferences. I didn’t see anything in the VDJML spec, but perhaps I’m wrong, @lindsay.cowell ?