LIRR Grand Central track labels in live data

[Sam]

Hey — quick question on LIRR live track labels.

I’m pulling data from the public LIRR GTFS-Realtime feed here:

https://api-endpoint.mta.info/Dataservice/mtagtfsfeeds/lirr%2Fgtfs-lirr

and I’m seeing Grand Central track values in two formats:

• 1, 2, 3, 4
• 201, 203, 204, 301, 302

Are 1–4 supposed to be shorthand / collapsed versions of the 200/300 series tracks, or are they meant to be interpreted as distinct values?

Mostly trying to understand the intended developer-facing meaning of those labels when consuming live LIRR track data.

If there’s any documentation or known convention for this, would appreciate a pointer.

Thanks