Documentation NR 1.6.3 Instrument Names

[Werner]

In the NR of version "2.11.57" I found:

Instrument names may be changed in the middle of a piece: 
     \set Staff.instrumentName = "First"
%     \set Staff.shortInstrumentName = "one"
     c1 c c c \break
     c1 c c c \break
     \set Staff.instrumentName = "Second"
%     \set Staff.shortInstrumentName = "two"
     c1 c c c \break
     c1 c c c \break


But this doesn't take effekt for me.
The new instrumentname doesn't appear at all.
(Only the shortname, if given, that means without the %, see above)

Also tested in 2.13.11.