Non-printing notes

[Jacques Menu]

Hello folks,

MusicXML has the 'print-object' attribute to notes, among other markups:

<note print-object="no">

<pitch>

<step>D</step>

<octave>3</octave>

</pitch>

<duration>768</duration>

<voice>6</voice>

<type>quarter</type>

<stem>down</stem>

<staff>2</staff>

</note>

This value ‘no’ is ignored by MuseScore and musicxml2ly, and Finale 2014b displays such notes in light gray this way, like the Ds and Gs below:

What is the intended meaning, and how should this be displayed using LilyPond?

Thanks for your help!

JM