ruler-mode-header-line-format

ruler-mode-header-line-format is a variable defined in `ruler-mode.el'.
Its value is

(:eval (funcall ruler-mode-ruler-function))

• This variable may be risky if used as a file-local variable.

Documentation:
`header-line-format' used in ruler mode.
Call `ruler-mode-ruler-function' to compute the ruler value.