Metadata capture and Meta Tagger

System

Validation-Regex on TextArea in metadacapture form doesn't work , if Item name is "Keywords".
<item name="Keywords">
<label>Keywords</label>
<database data-type="VARCHAR(255)" />
<textarea required="t" rows="4" cols="40" wrap="virtual" maxlength="255" validation-regex="^.(.|\n){0,254}$" />
</item>