questions about the TimeSig-context

[Stefan Thomas]

Dear lilypond-users,
I have again some questions concerning the TimeSig context.
I made a comment to those lines I do not understand. It would be very kind if someone could explain the mening of these lines to me.
Thanks!
Stefan
\layout{
 \context {
   \type "Engraver_group"
\consists "Bar_engraver"   
\consists "Span_bar_engraver"
\consists "Time_signature_engraver"
   \consists "Text_spanner_engraver"
   \consists "Text_engraver"
   \consists "Dynamic_engraver"
   \consists "Axis_group_engraver"
   \name "TimeSig"
   \override TimeSignature #'font-size = #3
   \override TimeSignature #'break-align-symbol = ##f % I don't understand the sense of it.
% I found out, that, if switched to #t the time-signature will not go left, although if there are clef changes in other voices.

   \override TimeSignature #'X-offset = #ly:self-alignment-interface::x-aligned-on-self %What does it do?
   \override TimeSignature #'self-alignment-X = #0
   \override TimeSignature #'after-line-breaking = #shift-right-at-line-begin %What does it do?
 }
 \context {
   \Score \accepts TimeSig
 }
 \context { \Staff
   \remove "Time_signature_engraver"
}
}