Bonjour Gérard,
Une solution :
\version "2.18.2"
#(allow-volta-hook "|")
#(allow-volta-hook "||")
voltaPourSuivre = \markup\text "Pour suivre"
voltaPourTrio = \markup\text "Pour Trio"
\relative c' {
\time 3/4
e2.~
%% option :
\override Score.VoltaBracket.edge-height = #'(3.0 . 3.0)
\override Score.VoltaBracketSpanner.padding = #2
\bar "||"
\set Score.repeatCommands = #(list (list 'volta voltaPourSuivre) 'start-repeat)
e4 r8 g\noBeam f e
\bar "||"
\set Score.repeatCommands = #(list (list 'volta voltaPourTrio) 'end-repeat)
e4 e ees
\set Score.repeatCommands = #'((volta #f))
}