Train Service fee

Well, as I know, the extra CNY5 is charged only when you buy the ticket in another place, which means you need to pay extra money if you buy A-B train ticket form C. In your case, if you buy the ticket from Pingyao to Xian at Pingyao Station, then no extra fee will be charged.

I understand that this fee is only payable if we COLLECT tickets booked from ticket agents or online at a train a station for rides departing from other cities. My questions are :
1. Does CNY5 also applicable to just BOOKING the ticket at the station for trains departing from
other cities ?
2. What if we only BOOK the tickets but collect at the departing station when we arrive. Taking Fionna's example - book Pingyao-Xian at Beijing Rail Station to secure the seats but collect the tickets at Pingyao station when they arrive. Does this work to avoid paying the CNY5 ?

May I ask is this rmb5 a collection fee or booking fee ?

CNY5 is the service fee when you collect or buy ticket for other journeys which won't start from the railway station.

As for question 1 of Patricia, yes, you understand it right. For your question 2, CNY5 is not needed in the mentioned case.

Thank you Leila. In other words, the stations will do the booking, as long as they do not need to issue the physical ticket for rides not originating from their station, they will not charge the CNY5 service fee.
Do I understand you correctly ?

Sorry to tell you, stations will not provide booking service, but I happen to know travelchinaguide has the ticket-booking service, and you can connect them through bookingtravelchinaguide.com

The railway stations don't provide the service of ticket booking, so if getting tickets there, they are physical ones. So if you get them for other routes that not depart from the city, CNY5 is needed.