Good Morning,
Here is my conundrum. Our organization has moved to 10.9.1 (finally) and I am stoked that I can finally bring in content from related data table layers into a feature layer popup. I was able to get the functionality working (i.e. grab related layer from a data table based on a common field) combine that data with some HTML tags for styling and then return the results (e.g. "<h1>" + filed_value + "</h1>"; ) so that it looks nice in the popup, the popup displays the HTML tags rather than rendering them (as they would if I just used the html tags in the popup directly. I realize that I could just return the data from the expression and style it as needed in the popup but the data that is return is a list of data (more than one record).
UPDATE (added Arcade Expression code and popup output):
var x = $feature['bail_go'];
var fs = FeatureSetByName($map, 'sureties');
var filt = Filter(fs,'bail_go = @x');
var cnt = Count(filt);
var sureties = "";
if (cnt > 0) {
for (var surety in filt) {
var bail_go = "<p><span style='color:#d6d6d6'><em>" + surety.bail_go + "</em></span></p>";
var txt_date = Text(surety.dob, ' - (Y/MM/DD) ');
var surety_tombstone_info = "<p><strong><span style='color:#d6d6d6'>" + surety.g1 + " " + surety.surname + "</span></strong> " + surety.sex + "- " + txt_date + "</p>";
var address = "<p>" + surety.address + ", " + surety.city + ", " + surety.province + ", " + surety.postal_code + "</p>";
var final = bail_go + TextFormatting.NewLine + surety_tombstone_info + TextFormatting.NewLine + address;
sureties += final;
}
} else {
sureties = "No Sureties";
}
return sureties;

Any guidance, insight, assistance is greatly appreciated.
Mark