We need type and variant on first contact please.
If departing, our systems check your FMS type when you request datalink clearance.
This doesn’t happen inbound or if you request a voice clearance outbound.
Yes, it’s on the flight plan, but you’d be surprised at how many time the flight plan is wrong. There are some types that fall into two wake categories depending upon variant, and this will become even more important when we move to pair-wise separation where B744-A321 pair will have different separation requirement than a B748-A320 pair.