Mentioning the caller is neither future-proof nor an adequate substitute
for giving an API specification.  Per gripe from Neha Khatri, though
I changed the patch around some.

Discussion: https://postgr.es/m/CAFO0U+_fS5SRhzq6uPG+4fbERhoA9N2+nPrtvaC9mmeWivxbsA@mail.gmail.com