RWY in FMA a320

[Jkotows2]

I understand it is identifying a localizer for the departure runway but is there a practical reason behind it?

Thanks

[EGPFlyer]

For use in low viz ops and helps you to maintain the centreline

[vilas]

Gives you the YAW bar to maintain center line for low visibility patches.

[A320ECAM]

The answers above are correct.