I'm a prepaid Vodafone user,  and over the last 3 days,  I've received three text messages (SMS) from a new acquaintance. 

My query is that the messages give their phone number and then on the line underneath their phone number it says "Reply cntr. defined",  their text message follows as normal.

I have never seen that on messages before,  can someone explain what it means and why I'm getting that from that person (it does not appear on messages from other people).