### 3.2.118 system-start-delimiter-interface

The brace, bracket or bar in front of the system. The following values for `style` are recognized:

`bracket`

  A thick bracket, normally used to group similar instruments in a score. Default for `StaffGroup`. `SystemStartBracket` uses this style.

`brace`

  A ‘piano style’ brace normally used for an instrument that uses two staves. The default style for `GrandStaff`. `SystemStartBrace` uses this style.

`bar-line`

  A simple line between the staves in a score. Default for staves enclosed in `<<` and `>>`. `SystemStartBar` uses this style.

`line-bracket`

  A simple square, normally used for subgrouping instruments in a score. `SystemStartSquare` uses this style.

See also ‘`input/regression/system-start-nesting.ly`’.

#### User settable properties:

> `collapse-height` (dimension, in staff space)

>   Minimum height of system start delimiter. If equal or smaller, the bracket/brace/line is removed.

> `style` (symbol)

>   This setting determines in what style a grob is typeset. Valid choices depend on the `stencil` callback reading this property.

> `thickness` (number)

>   Line thickness, generally measured in `line-thickness`.

This grob interface is used in the following graphical object(s): SystemStartBar, SystemStartBrace, SystemStartBracket and SystemStartSquare.

#### Internals Reference v2.18.2 (稳定分支).