diff --git a/core/models/survex.py b/core/models/survex.py
index b7c0b9b..cc9b9f8 100644
--- a/core/models/survex.py
+++ b/core/models/survex.py
@@ -155,11 +155,11 @@ class SurvexBlock(models.Model):
 
 class SurvexPersonRole(models.Model):
     survexblock         = models.ForeignKey('SurvexBlock',on_delete=models.CASCADE)
-        # increasing levels of precision
+        # increasing levels of precision, Surely we only need survexblock and person now that we have no link to a logbook entry?
     personname          = models.CharField(max_length=100)
     person              = models.ForeignKey('Person', blank=True, null=True,on_delete=models.SET_NULL)
     personexpedition    = models.ForeignKey('PersonExpedition', blank=True, null=True,on_delete=models.SET_NULL)
-    persontrip          = models.ForeignKey('PersonTrip', blank=True, null=True,on_delete=models.SET_NULL)  
+    persontrip          = models.ForeignKey('PersonTrip', blank=True, null=True,on_delete=models.SET_NULL)   # logbook
     expeditionday       = models.ForeignKey("ExpeditionDay", null=True,on_delete=models.SET_NULL)
     
     def __str__(self):