Comment 7 for bug 1736911

@bhill I'm sure you're aware that the pvAccess userTag is current defined as an int32 in pv/timeStamp.h, so you'll also need to propose that it be widened to make it 64-bit (I would support making it unsigned as well if we do decide to change it). This will have knock-on effects and require changes to other modules which may trigger some push-back, so if that's your plan please create an issue (on Github) against both the pvDataCPP and pvDataJava modules to start that discussion.