1\version "2.21.0"
2
3\header {
4  texidoc="Rehearsal_number_engraver may be moved to staff-group
5contexts.  Five marks should appear in black above the second staff
6from the top.  The same marks should appear in red above the third
7staff from the top."
8}
9
10\layout {
11  \context {
12    \Score
13    \remove "Mark_engraver"
14  }
15}
16
17<<
18  \new Staff {
19    s1*4
20  }
21  \new ChoirStaff \with {
22    \consists "Mark_engraver"
23    \consists "Staff_collecting_engraver"
24  } <<
25    \new Staff {
26      s1*4
27    }
28    \new StaffGroup \with {
29      \consists "Mark_engraver"
30      \consists "Staff_collecting_engraver"
31      \override RehearsalMark.color = #red
32    } <<
33      \new Staff \relative {
34        s1*4
35      }
36      \new Staff \relative {
37        \mark "Α"
38        c'1 \mark "foo"
39        c1
40        \key cis \major
41        \clef alto
42        \override Score.RehearsalMark.break-align-symbols = #'(key-signature)
43        \mark "on-key"
44        cis
45        \key ces \major
46        \override Score.RehearsalMark.break-align-symbols = #'(clef)
47        \clef treble
48        \mark "on clef"
49        ces
50        \mark "Ω"
51      }
52    >>
53  >>
54>>
55