Spotted some different legend on back of 2 MPC60's

In the MPC60 instruction video I noticed Rogers MPC60 says " 4/sync " above MIDI output 4, as seen here at 1:02


On my MPC60 it only says " 4 "

Have there been any other changes to front or rear panel legend ?
Anyone know why/when it changed ?
Is this old news and I'm just a bit slow ?

Roger had a prototype in his possession, is it likely that this is what you have seen?

Beatdiggerjazzcat wrote:Roger had a prototype in his possession, is it likely that this is what you have seen?

Soz, link was broke.
I'm comparing the MPC in the video (important part at 1:02) to my own MPC.