Arguments that appear like so in the usage:

f(..., arg = opt(DEFAULT), ...)

get their value according to this logic:

user-specified value or, if not given,
  getOption("reprex.arg") or if does not exist,
    DEFAULT

It's shorthand for:

f(..., arg = getOption("reprex.arg", DEFAULT), ...)

This is not an exported function and should not be called directly.

Details

Many of the arguments of reprex() use opt(). If you don't like the official defaults, override them in your .Rprofile. Here's an example for someone who dislikes the "Created by ..." string, always wants session info, prefers to restyle their code, uses a winky face comment string, and likes the tidyverse startup message.

options(
  reprex.advertise = FALSE,
  reprex.si = TRUE,
  reprex.style = TRUE,
  reprex.comment = "#;-)",
  reprex.tidyverse_quiet = FALSE
)