Hello GeoNet Community!
One idea that I would like to see implemented is the ability to publish a service containing data formatted with HTML tags to ArcGIS Server. Two examples showing how this could benefit users are shown below.
Sending live data feeds to GeoEvent Processor for incident monitoring.
Referenced: GeoEvent tutorial guide - Working with RSS in ArcGIS GeoEvent Processor.pdf
Sending formatted Emails to customers. See the GeoEvent 'Send an Email' 10.4 enhancement.
Please let me know when this feature becomes available in ArcGIS Server.