For US Section 508 compliance, you should not use visual cues like bold typeface for this. Instead, use a naming convention, like adding ' *' to the end of all required fields labels.
Did anything change regarding this in Mendix since 5 years? Or is the best practise still to simply add a "*" for every field which is required :)?
It would be nice if Mendix added a class for the required fields.
An option that works is adding a (custom) class to the field. for example: mandatory
Add some css to the custom.css:
.mandatory label.control-label::after {
content: " *";
}
All fields where you enter the class mandatory will get an * added to the label.
You could use the 'place holder' attribute. I like to set it to 'required'.