<rng:optional><rng:attribute name="required"/></rng:optional>
<rng:optional><rng:attribute name="readonly"/></rng:optional>
<rng:optional><rng:attribute name="view_mode"/></rng:optional>
+ <rng:optional><rng:attribute name="search_mode"/></rng:optional>
<rng:optional><rng:attribute name="widget"/></rng:optional>
<rng:optional><rng:attribute name="context"/></rng:optional>
<rng:optional><rng:attribute name="groups"/></rng:optional>