nroff-font-lock-keywords

nroff-font-lock-keywords is a variable defined in `nroff-mode.el'.
Its value is

("^[.']\\s-*\\sw+" "\\\\\\([f*n]*\\[.+?]\\|(..\\|[^(\"#]\\)")

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

Documentation:
Font-lock highlighting control in `nroff-mode'.

You can customize this variable.