shape. Objects with an extended shape like these are called
@q{Spanners}.
+Spanners cannot be tweaked after their creation. This includes both
+@code{StaffSymbol} and @code{LedgerLineSpanner} which continue
+throughout the score (except if they are terminated by the
+@code{\stopStaff} command and then recreated using @code{\startStaff}
+command.
+
What is more, there are @q{abstract} grobs which do not print
anything of their own, but rather collect, position and manage
other grobs. Common examples for this are
modified by different commands, so it is useful to be able to recognize
the types of objects and properties from their names.
+@seealso
+Notation Reference:
+@ruser{Modifying properties}.
+
@node Tweaking methods
@subsection Tweaking methods