rests in parentheses

[lemzwerg]

In a very old MusicXML test file I found the following to produce a rest in parentheses:

<note>
  <rest/>
  <duration>1</duration>
  <voice>1</voice>
  <type>quarter</type>
  <notehead parentheses="yes">normal</notehead>
</note>

Is this a valid interpretation? It doesn't really make sense to have <rest> combined with <notehead> – except for the possible side effect of the parentheses attribute.

To me it is not clear at all why <notehead> and <accidental> both have a parentheses attribute while <rest> has not. It feels unbalanced.

Additionally, using <level> doesn't feel right for some situations. As a composer, I have actually parenthesized rests by myself, which essentially means that the parentheses are not something added later by the editor... On the other hand, I can understand that there are so many different MusicXML elements that adding a parentheses attribute to all of them might not be prudent.