Examples from "Common Particles Configuration" section of the form reference: form.mustvalue - an optional field is *displayed* as required when form.mustvalue=true

Field Required *Required field that when HTML5 is enabled does not admit the empty string

Field Required Must Value False(Optional)

Field Required Form Empty True(Optional)This input is required but accepts the empty string, also when using html5

Field Optional(Optional)This control binds the empty input to an absent value

Field Optional Must Value *

Field Optional Form Empty False(Optional)

Field Optional Form Required True *

Field Optional Form Empty False Req True *

Field Must Value No Html 5 *Also if is displayed as required this field can be submitted without value since html5 [required] is not used...there's no validation involved, as usual constraints must stay in schema, this is just a visualization configuration