ReadonlyallowedReadonlyfollowalso report what the hook does through functions of the package it calls, which R CMD check does not see (default true)
Readonlystartupfunctions that print startup messages the way R wants them to, which are only allowed in .onAttach
Readonlyunsafefunctions too costly or unsafe to call in a startup hook (default installed.packages)
functions that may emit output in a startup hook nonetheless, as the user can silence them otherwise (default
warning)