+
+ADD_INTERFACE (Staff_symbol, "staff-symbol-interface",
+ "This spanner draws the lines of a staff. "
+ "A staff symbol definines a vertical unit, the staff space. "
+ "Quantities that go by a half staff space are called positions "
+ "The center (i.e. middle line "
+ "or space) is position 0. The length of the symbol may be set by hand "
+ "through the @code{width} property. ",
+
+ "ledger-line-thickness width staff-space thickness line-count");