Specifies that this field must be filled in by the user. Note: mandatory should not be used in conjunction with hidden. Use of both in any field will cause the mandatory check on any field to fail when the form is saved. see http://www.mediawiki.org/wiki/Extension:Semantic_Forms/Defining_forms#.27field.27_tag
Property mandatory# QUERY8ca01daeb06cd167d6ad749390f865bf