no : in yaml files unless you are using them to demote new objects

data/talks.yaml

@@ -7,7 +7,7 @@ cards:
   - meeting: Eurohack 2017
     location: Lugano, CH
     date: September 2017
-    title: SWIFT: Hackathon Final Presentation
+    title: "SWIFT: Hackathon Final Presentation"
     author: Matthieu Schaller & Josh Borrow
     abstract: "Final talk at Eurohack after working on the code for the week to improve performance."
     links: