diff --git a/src/services/trainService.services.js b/src/services/trainService.services.js
index ced4991..037eb5d 100644
--- a/src/services/trainService.services.js
+++ b/src/services/trainService.services.js
@@ -20,6 +20,16 @@ async function findByHeadcode(headcode) {
   const trainData = db.query('timetable', query);
   return trainData; // Use pis.findByTiplocArray() to return a PIS code alongside the data
   // eg. {trainData: {}, pis:5001}
+  // Will need to do something like:
+  /* for i in trainData {
+       let tiplocArray = []
+       for ii in i['stops'] {
+         get TIPLOC
+         push TIPLOC to tiplocArray
+       }
+       const pis = pis.findByTiplocArray(tiplocArray)
+      }
+      */
 }
 
 module.exports = {