The note is the typical method for documenting this at my office as well. I have considered adding version numbers to this due to renaming issues as packages grow and change, but have held off because it felt redundant.
Out of curiosity, how would a graph read the correct version of a node in the illustrated example? If I create a graph and have archilab 1.12.10 and @Ewan_Opie opens it and has 1.13.2 do we both see 1.12.10 as I wrote it with that or does he see 1.13.2?
You guys know that right clicking and getting the properties will indicate the data about the package including the sub heading, right?