Idea Summary
Support HTML tag inside the apex.message.* function. Currently this is working if use a DA as Alert or Confirm but if you use Java script then it display the tags on the message.

Use Case
var info = apex.item("P1_PROMPT_ALERT").getValue();
var title = $v('P1_ALERT_TITLE');
var summary = $v('P1_ALERT_SUMMARY');
var act = $v('P1_ALERT_ACTION');
apex.message.confirm( summary+"\n"+info+"\n" +"<strong>"+act+"</strong>", function( okPressed ) {
if( okPressed ) {
window.location.reload();
}
else{
apex.navigation.dialog.close(true);
} }
, {
title: title,
style: "warning",
cancelLabel: "Cancel",
confirmLabel: "Get Data"
} );
https://forums.oracle.com/ords/apexds/post/apex-message-confirm-showing-html-tag-in-confirm-alert-5480