The 'userfield' and 'coursefield' elements load the custom fields for these types. If you are referring to something else please provide more context or even a Moodle docs page showing this feature. Thanks!
Custom certificate (plugin)
Need to use Dynamic Fields
Гэтае абмеркаваньне было заблакавана, таму вы болей ня можаце адказваць на яго.