Cross posted on Wolfram Community.
Mathematica cannot represent edge properties in multigraphs (except for EdgeWeight, EdgeCapacity and EdgeCost). This is a very severe limitation when using Mathematica for network analysis because there are many datasets out there which have both parallel ed...
@Szabolcs It's very curious how they get some things wrong. You'd think that it's just a matter of importing some database from somewhere; are mistakes like this common in name databases? Recently, I discovered that US counties now have FIPS codes in their entities. Before, FIPS codes were all either missing or wrong, now 90% are right. But why 90%? How did they get 10% wrong? Wikipedia, for example, has a list that is 100% correct.